INCIDENCE OF HISTOLOGICALLY DIAGNOSED CANCER IN SOUTH AFRICA,

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1 INCIDENCE OF HISTOLOGICALLY DIAGNOSED CANCER IN SOUTH AFRICA, Nokuzola Mqoqi, 1 MSc (University of Natal), M.Sc. (PHDC) (LSHTM, University of London) Patricia Kellett, 1 Dip.Med. Tech (Wits Technikon) Freddy Sitas, 2 D. Phil. (University of Oxford) Musa Jula, 1 N. Dip IT (Technikon SA) NATIONAL CANCER REGISTRY The National Cancer Registry is a co-operative venture of the Department of Health, the Cancer Association of South Africa, the National Health Laboratory Service and the University of the Witwatersrand Department of Anatomical Pathology, School of Pathology, Wits University 1 National Health Laboratory Service (Previously SAIMR) P O Box 1038, Johannesburg, 2000, South Africa The Cancer Council, New South Wales 2 P O Box 572, Kings Cross, New South Wales, 1340, Australia Published by the National Cancer Registry of South Africa, National Health Laboratory Service, Johannesburg. December 2004 cancer98_contents 1 4/4/05, 14:37

2 CONTENTS LIST OF FIGURES i LIST OF TABLES ii NATIONAL CANCER REGISTRY iii FOREWORD iv CHAIRPERSON S COMMENT v ACKNOWLEDGEMENTS vi FUNDING vii EXECUTIVE SUMMARY viii ACRONYMS x 1. INTRODUCTION 1 2 METHODS Data collection and data flow Reporting of cancer Data quality and quality assurance Completeness of data Unique identification and use of names Analysis International comparison Presentation of cancer incidence report RESULTS Data reported in 1998 and Frequency of new cancers in 1998 and Age distribution of cancer cases Distribution of cancer sites by age group Incidence of cancer in 1998 and Cancer by site Cancer of the Bladder Cancer of the Cervix Colorectal cancer Colon cancer Female breast cancer Kaposi sarcoma Lung cancer Melanoma Non-Hodgkin lymphoma Non-Melanoma skin cancers Oesophagus cancer Prostate cancer Cancer of the Uterus SUMMARY REFERENCES 55 cancer98_contents 2 4/4/05, 14:38

3 LIST OF FIGURES Figure 1: Map of South Africa 2 Figure 2: South Africa s population, Figure 3: Percentage distribution of cancer cases by race and year of diagnosis 7 Figure 4: Percentage distribution of cancer cases by diagnosing province and sex, 1998 and 1999 combined 12 Figure 5: Percentage distribution of cancers by years of diagnosis and population group 12 Figure 6: Percentage distribution of new cancer cases reported in 1998 and 1999 by age groups and sex (includes BCC and SCC of skin) 13 Figure 7: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 All ages 14 Figure 8: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 Ages 0-14 years 14 Figure 9: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 Ages years 15 Figure 10: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 Ages years 15 Figure 11: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 Ages years 16 Figure 12: Percentage distribution of 10 most common cancers by sex, 1998 and 1999 Ages Figure 13: Age specific incidence rates for bladder cancer by population group, Figure 14: Bladder cancer ASR per for selected populations 21 Figure 15: Age specific incidence rates for cervix cancer by population group, Figure 16: Cervix cancer ASR per for selected populations 23 Figure 17: Age specific incidence rates for colorectal cancer by population group, Figure 18: Colorectal cancer ASR per for selected populations 26 Figure 19: Age specific incidence rates for colon cancer by population group, Figure 20: Colon cancer ASR per for selected populations 29 Figure 21: Age specific incidence rates for female breast cancer by population group, Figure 22: Female breast cancer ASR per for selected populations 31 Figure 23: Age specific incidence rates for Kaposi sarcoma by population group, Figure 24: Kaposi sarcoma ASR per for selected populations 34 Figure 25: Age specific incidence rates for lung cancer by population group, Figure 26: Lung cancer ASR per for selected populations 37 Figure 27: Age specific incidence rates for melanoma by population group, Figure 28: Melanoma ASR per for selected populations 40 Figure 29: Age specific incidence rates for non-hodgkin lymphoma by population group, Figure 30: Non-Hodgkin lymphoma ASR per for selected populations 43 Figure 31: Age specific incidence rates for non-melanoma skin cancers by population group, Figure 32: Non-melanoma skin cancers ASR per for selected populations 46 Figure 33: Age specific incidence rates for oesophagus cancer by population group, Figure 34: Oesophagus cancer ASR per for selected populations 49 Figure 35: Age specific incidence rates for prostate cancer by population group, Figure 36: Prostate cancer ASR per for selected populations 51 Figure 37: Age specific incidence rates for uterus cancer by population group, Figure 38: Uterus cancer ASR per for selected populations 53 i cancer98_prelim 1 4/4/05, 14:38

4 LIST OF TABLES Table 1: Direct Standardisation method for the cancer of the cervix in black females, Table 2: Frequency distribution of cancer diagnosing laboratories and cancers diagnosed in 1998 and 1999 by province 11 Table 3: Frequency distribution of cancers by population group, sex and year of diagnosis 13 Table 4: Summary rates for the leading five cancers by race group and sex, 1998 and Table 5: Summary statistics for bladder cancer, 1998 and Table 6: Summary statistics for cervix cancer, 1998 and Table 7: Summary statistics for colorectal cancer, 1998 and Table 8: Summary statistics for colon cancer, 1998 and Table 9: Summary statistics for female breast cancer, 1998 and Table 10: Summary statistics for Kaposi sarcoma, 1998 and Table 11: Summary statistics for lung cancer, 1998 and Table 12: Summary statistics for melanoma, 1998 and Table 13: Summary statistics for non-hodgkin lymphoma, 1998 and Table 14: Summary statistics for non-melanoma skin cancers, 1998 and Table 15: Summary statistics for oesophagus cancer, 1998 and Table 16: Summary statistics for prostate cancer, 1998 and Table 17: Summary statistics for cancer of the uterus, 1998 and ii cancer98_prelim 2 4/4/05, 14:38

5 FOREWORD The cancer incidence report represents an important source of information for our understanding of cancer incidence patterns among the different race groups in South Africa. This report is a result of the dedication of the National Cancer Registry staff and academicians in the fields of oncology, pathology, histology and Epidemiology. The support from the private laboratory groups is acknowledged and represents a key aspect of public-private partnerships. The report is aimed at generating data on the important trends and patterns in histologically confirmed cancer among the South African population. The National Cancer Registry makes it possible for us to monitor and quantify the burden of cancer disease in our country by publishing cancer incidence nationally. We know that 25% of South African men and 20% of South African women will at some stage in their lifetime develop a cancer; and which cancers are most prevalent in which population groups, sex and age categories. Availability of this information has helped us to think more and focus our goals concerning cancer disease. Our goal is to reduce morbidity and mortality from cancer and improve the quality of life of cancer patients. Important initiatives to prevent and control cancer are being implemented by the Department of Health. These include the amendment of the Tobacco Products Control Act in 1999, a government effort to reduce lung cancer and other upper respiratory tract conditions, of which tobacco smoking is known to account for a large proportion. We are also implementing a cervical cancer screening programme amidst some logistical challenges in order to ensure effective implementation of this programme. I have also observed with alarm the increasing incidence of breast cancer that is catching up with that of cancer of the cervix in all population groups. These patterns are sending strong and bold messages for prevention and control. Whilst the Department of Health has to come up with cost-effective interventions, I am keen on future and more upto-date trends on these cancers as an evaluation measure to evaluate our prevention initiatives. My sincere wish is that these statistics will assists us in implementing our interventions and addressing issues of inequity and inequality, particularly as we see large disparities and inequity in availability of diagnosing facilities in the nine South African provinces. Furthermore these statistics should talk more to other areas of cancer prevention and control including educating communities and creating awareness and clinical and palliative management of patients. This report mentions gaps in cancer knowledge in the African context and I would like to call upon all researchers in the cancer field to engage in research that will consider resource limitations as well as other diseases competing for the same resources. I would like to call upon all stakeholders to commit and participate in a comprehensive cancer prevention and control approach. This report was made possible through the dedication and commitment of a number of individuals. I would like to extend my thanks to all who have made the completion of this report possible. Dr ME Tshabalala- Msimang Minister of Health iv cancer98_prelim 4 4/4/05, 14:38

6 CHAIRPERSON S COMMENT The National Cancer Registry, which was first established in 1986, was taken over and developed by Dr Freddy Sitas who moulded it into its present shape between 1991 and It plays a critical role in maintaining and developing national and international awareness of the enormous and growing problem of cancer among the South African population. Cancer is one of the major killers throughout the world, including South Africa. Indeed, South African males have a lifetime risk of 1 in 4 of developing cancer, while South African females have a lifetime risk of 1 in 6 of developing cancer. This report, covering the years , will be widely used and quoted by many organisations both in the public and private sectors. Government bodies, including the Departments of Health, Home Affairs and Finance, need to know how many people develop and die from cancer, while this information is critical to many private sector bodies including medical aids, insurance companies, pharmaceutical companies, private hospital groups and financial institutions. Although this is a pathology-based registry, resulting in the under-reporting of many malignancies, some more than others, many critical decisions will be made based on its data. Future population based registries will be vital, especially when decisions on screening, prevention, as well as treatment are made. The latest Registry data once again shows fascinating but worrying trends in the South African cancer statistics when compared to its predecessor. Males have a lifetime risk of 1 in 4 of getting cancer as opposed to 1 in 6 in the previous report, with cancers of the prostate, lung, oesophagus, bladder and colon/rectum still predominating. Prostate cancer remains the most common major cancer in men with lung and oesophagus cancer following closely behind. In women the lifetime risk of getting cancer is now 1 in 6, as opposed to 1 in 7 in the previous report, with cancer of the uterine cervix and cancer of the breast predominating with very similar incidences. Colorectal and oesophageal cancer follow, as was the case in Lung cancer remains a growing health problem in both sexes. Although males far exceed females, the long term effects of smoking will result in an increasing incidence of lung cancer in females in years to come. It will be many years before recent anti-smoking drives and legislation reduce these figures. As previously mentioned, the reporting of many cancers is inadequate due to a lack of tissue diagnoses. An important example is hepatocellular carcinoma which is grossly under-reported, due to the lack of tissue diagnoses, but which nevertheless remains among the top 15 cancers. Well over a million new cases a year are diagnosed throughout the world, and as southern Africa, along with the Far East, are endemic areas for the hepatitis B virus, the major causative agent of this disease, hepatocellular carcinoma remains a major health problem in our country. Future populationbased registries and better cancer diagnoses, especially in rural areas, will hopefully give us a more accurate picture of this usually fatal malignancy, as well as many other under-reported cancers. Funding remains a major problem for the registry, which relies on support mainly from the National Health Laboratory Service, and to a lesser extent, the Cancer Association of South Africa and the Department of Health. The task of collecting and analysing data from most pathology laboratories throughout South Africa is an enormous one and requires a dedicated staff as well as advanced computer and statistical support. This is a costly exercise which requires funding from both the private as well as the public sectors to increase the efficiency of data collection and analysis, especially if population-based registration is to occur. We hope that we will soon be able to broaden our support base to involve all role players in the health care sector; this will enable us to maintain and develop this national asset well into the future. On behalf of the Scientific Advisory Committee, I would like to congratulate Ms Nokuzola Mqoqi, Ms Patricia Kellett, Mr Musa Jula and the rest of the NCR staff for their tremendous work in completing this report, as well as to thank the many state and private laboratories who have contributed data to the Registry, and without whom this report would not have been possible. Professor Paul Ruff, Chairperson, Scientific Advisory Committee and Head, Division of Medical Oncology, Department of Medicine, University of the Witwatersrand Faculty of Health Sciences. v cancer98_prelim 5 4/4/05, 14:38

7 EXECUTIVE SUMMARY Amidst the enormous burden of communicable diseases, non-communicable diseases are also emerging as a significant challenge competing for limited resources in developing countries. After 18 years in operation, the NCR continues to measure and publish the incidence rates of pathology-confirmed cancers in South Africa in an attempt to inform cancer control efforts nationally. Towards the end of 1999, the cancer registry started seeing the merger of smaller with bigger laboratories. The number of cases reported is not expected to decrease as a result of these mergers and it is important for the registry to monitor the laboratories closely in order to keep track of any changes. The registry receives pathology reports from all public and private pathology laboratories nationally. In the absence of any legislative framework of disease reporting, pathology laboratories have voluntarily provided data to the Registry since its inception. This ongoing national collaboration of all the laboratories across private and public sectors is remarkable. In keeping with emerging concerns about privacy, ethical guidelines to receive and hold this information are being developed. Since 1992, cancers have been coded and classified following the WHO/International Agency for Research on Cancer ICD-O-1 and were reported in ICD-10 following DOH reporting requirements. Changes in methodologies were implemented and included coding of 1999 data using ICD-O second edition. The aim is to keep up with new research findings in the oncology field and update emerging cancers. Key variables collected include primarily the patient demographic data and tumor information. Missing information on population groups remains a major concern, making it difficult to discern important cancer incidence patterns by population group. About twothirds of the collected data in 1998 and three quarters of that in 1999 did not report on the population group of cases. Hot-deck imputation methods have been developed in an attempt to provide some continuity. Monitoring cancers by population group would enable the registry to further extend and evaluate the effectiveness and equity of access of the newly implemented cervical cancer and tobacco control policies, using the existing cancer registry data as a baseline for these programs. Considering the differences in service delivery in the South African health system in the past, which influenced and dictated availability and access to health facilities and, directly or indirectly, the health seekingbehaviour patterns of different population group; monitoring of disease across different population groups is critical to measure the equity efforts in different parts of the country as well as health outcomes in different races. The largest proportion (40%) of new cancer cases was diagnosed in the Gauteng Province which had the highest number of cancer diagnosing facilities (25), with KwaZulu-Natal and the Western Cape Provinces diagnosing 18.6% and 18% respectively. A total of and new cancer cases were reported to the NCR in 1998 and 1999 respectively. Females comprised 50.5% and 50.9% of all cancer cases diagnosed in the two consecutive years and males comprised 49.5% and 49.1% of all cancer cases in 1998 and 1999 respectively. On average, the white population comprised 46% of all cancer cases (but this includes many basal and squamous cell skin cancers, which are normally excluded by other registries). In 1998, the black population comprised 39.4% of all cases and 36.8% of all cases reported in Asians comprised the lowest proportion of all races, an average of 2.2%. The lifetime risk (ages 0 to 74 years) of developing cancer in South African males and females remained the same as that reported in 1997, with one in four males and one in five females when adjusted for under-reporting. Cancers of the prostate, lung, oesophagus, colorectal and bladder, in that order, were the five leading cancers in males. In 1999, one in 24 men was at risk of developing the cancer of the prostate and one in 59 men was at risk of developing cancer of the lung. In females, cancers of the breast, cervix, colorectum, oesophagus and uterus were, in order, the five leading cancers. In the two years, one in 27 women was likely to develop cancer of the breast in their lifetime and the lifetime risk of developing the cancer of the cervix was one in 31. Childhood cancers comprised on average 1% of all female cancers and 2% of all cancers in males reported in 1998 and The top four common childhood cancers in males aged 0 14 years in order, were leukemia, brain, kidney and non-hodgkin lymphoma, constituting 53% of all male childhood cancers. In females in the same age category and in order, leukemia and cancers of the kidney, brain and bone were the four most common cancers constituting 55% of all female childhood cancers. Important population differences exist. Cancer of the cervix remained the leading cancer in black females in 1999, with lifetime risk of one in 25 black women compared to one in 21 in 1998, at risk of developing the cancer of the cervix. Cancer of the breast was the leading cancer in Asian, coloured and white females. One in 12 white women had a lifetime risk of developing the cancer of the breast. Overall, lower rates than those reported in 1997 and 1998 were viii cancer98_prelim 8 4/4/05, 14:38

8 reported for the cervix and prostate cancer. Variations in incidence rates were also observed for some sites, for example, cancer of the lung in males, whilst other sites sustained consistent rates over the years, for example, colorectal cancer in both males and females, and uterus cancer. In some of the leading cancers an increase in the risk of developing these cancers was observed. For example, the lifetime risk of developing breast cancer in all females increased from 1 in 31 in 1997 to 1 in 27 in 1999, and in black females it increased from 1 in 57 in 1997 to 1 in 49 in White men and women had the highest incidence rate for colon cancer of 16.5 and 11.8 per , respectively. Amongst cancers known to be associated with HIV/AIDS, Kaposi sarcoma (KS) was the third most common cancer in both males and females aged years, and comprised on average nine percent of all female and male cancers in this age group. Relative to other cancers, KS was still rare and low rates were observed, especially in Asians, coloureds and whites. Contrary to most cancers where the age specific incidence rates peak at older ages, the age standardized incidence rates for KS showed a bimodal pattern in most race groups with the highest peaks occurring early in life at ages in females and in males. Very little change occurred in Non-Hodgkin lymphoma in the two years compared to the previous years. Cancer incidence rates in South Africa are among the highest rates reported in Africa. Monitoring cancer incidence is important in detecting changes in cancer patterns that might occur as a result of changes in environmental conditions, association with new diseases, to detect new cancers and to measure effectiveness of currently implemented cancer control programs. Increased efforts should concentrate on establishing comprehensive cooperative regional registration systems and on ensuring long term sustainability of existing registries. ix cancer98_prelim 9 4/4/05, 14:38

9 3. RESULTS The distribution of the cancer burden in 1998 and 1999 is presented by age groups, sex and race. Detailed frequency distribution tables and cancer site incidence rates are attached at the back of the report. Only the five leading cancers with the highest incidence rates (ASR) in males and females together with some cancers of particular interest are discussed below. 3.1 Data reported in 1998 and 1999 A total of new cancer cases in 1998 and 1999 combined, were reported to the cancer registry from 84 reporting units from laboratories countrywide. The number of laboratories sending data has decreased since 1999 due to the merger of smaller laboratories with larger laboratories. The cancer registry is closely monitoring such trends in order to explain any changes that may occur in our data. Up to now, no significant changes have been observed as a result of these mergers. The largest proportion of cases (40.8%) was reported from 25 laboratories in the Gauteng province (GP) (Table 2). The second highest proportion of cases (18.6%) was reported from 11 laboratories in KwaZulu-Natal (KZN). Table 2: Frequency distribution of cancer diagnosing laboratories and cancers diagnosed in 1998 and 1999, by province Province No. of labs % of labs *No. of cases % of cases Eastern Cape Free State Gauteng KwaZulu-Natal Limpopo Mpumalanga Northern Cape North-West Western Cape Total *Please note: these figures reflect service provision rather than burden of cancer per province. The Western Cape province (WC), with 16 laboratories, reported about 18% of all cancer cases. About five percent of all cases were diagnosed from eight laboratories in four rural provinces including Limpopo (LP), Mpumalanga (MP), Northern Cape (NC) and the North-West (NW). There was no significant difference in the proportions of male and female cancer cases diagnosed in each province (Figure 4). At present, the burden of cancer disease by province cannot be estimated from the available NCR data. This is due to a lack of information on patient addresses. Most clinicians are aware that patients cross provincial borders from less to better-resourced provinces to seek better treatment. Because of existing health policies governing provincial boundaries, patients tend to give local rather than their home addresses. In addition to patient movement, some health practitioners send their patient specimens to other provinces for diagnosis. All these factors reflect the services provided by each province on cancer management rather than the true burden of cancer by province. In an effort to get a better understanding of the burden of cancer cases by province, it is recommended that population-based cancer registries be established in the nine provinces. The Department of Health guidelines on cancer prevention and control (DOH, 2002) recognises this fact and has recommended the establishment of a rural and urban population-based cancer registry in each of the nine provinces. Until such recommendations come into effect, estimation of cancer incidence by province will remain a difficult task. 11

10 Figure 4: Percentage distribution of cancer cases by diagnosing province and sex, 1998 and 1999 combined n=25 Males Females 35 Percentage Percentage n=14 n=10 n=11 n= n=1 n=3 n=2 n=2 EC FS GP KZ LP MP NC NW WC Province 3.2 Frequency of new cancers in 1998 and 1999 There were new cancer cases reported to the cancer registry in 1998 and new cases in In both 1998 and 1999, female cancer cases comprised half of all reported cases. Overall, Whites comprised the highest proportion of all cancer cases, comprising 45.2% and 46.4% in 1998 and 1999 respectively (Figure 5). The second highest proportion of new cancer cases comprised Blacks, with 39.4% of all cancer cases in 1998 and 36.8% in Figure 5: Percentage distribution of cancers by years of diagnosis and population group Percentage Percentage Asian Black Coloured White Unknown Population group 12

11 Black women comprised the largest proportion of all female cancer cases, constituting 44.1% and 41.7% in 1998 and 1999 respectively (Table 3). The second-highest proportion of all female cancer comprised white females who constituted 40.3% of all female cancers in 1998 and 41.3% in One half of all male cancer cases in the two years were white males, whilst black males comprised about one third of all male cancer cases. In line with South African demographics, the Asian population had the lowest number of reported cases. Table 3: Frequency distribution of cancers by population group, sex and year of diagnosis (% of the total in parentheses) Sex / Population No. of cases Percentage No. of cases Percentage Females Asian Black Coloured White Unknown All females (50.0) (50.5) Males Asian Black Coloured White Unknown All males (49.0) (48.8) Unknown sex 580 (1.0) 435 (0.7) TOTAL (100) (100) 3.3 Age distribution of cancer cases Children (0-14 years) comprised one percent of all female cancer cases, whilst young women aged between 15 and 29 years comprised four percent of the total female cancer cases in 1998 and The largest proportion (37%) of cancers occurred in women aged between 30 and 54. Elderly women aged 65 years and older comprised about one third of all female cancers. Two percent of all male cancers were reported in children, and three percent in young men aged between 15 and 29 years old. The majority of cancers (40%) were reported in elderly men aged 65 years and older (Figure 6). Figure 6: Percentage distribution of new cancer cases reported in 1998 and 1999 by age groups and sex (includes BCC and SCC of skin) Unknown Females (N= ) % 1% 4% Males (N=56 577) Unknown 4% % % % % % % % %

12 3.3.1 Distribution of cancer sites by age group The frequency distribution of the top 10 cancers in all age groups is shown in Figure 7. Of all the cancers in females, breast, cervix and BCC cancers comprised more than half of those reported in 1998 and Cancer of the breast was the most common cancer in females and comprised 19% of all female cancer cases in the two years. Cancer of the cervix was the second most common, comprising 18.6% of all female cancer cases. In males, BCC and prostate cancers remained the first and second most common cancers, with prostate comprising 13.6% of all male cancers. Figure 7: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, All ages Males (n = ) Females (n = ) BCC Breast Prostate Cervix SCC of skin BCC Lung SCC of skin Oesophagus Oesophagus Colorectal Colorectal Bladder Ovary Stomach Uterus Melanoma Lung Larynx Melanoma Other sites Other sites Percentage In children (ages 0-14 years), leukemia was the most common cancer comprising about a quarter of all cancers in males and females. Leukemia, brain, kidney, non-hodgkin lymphoma and eye cancers, (in that order), comprised the five most common cancers in male children, with proportions of the total cancers in this age group ranging between 6.7% and 24% (Figure 8). In female children, the five most common cancers (in that order), were leukemia, kidney, brain, bone and non-hodgkin lymphoma, with proportions ranging between 5.3% for NHL and 24.7% for leukemia. Figure 8: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, 0-14 years Males (n = 1096) Females (n = 758) Leukaemia Leukaemia Brain Kidney Kidney Brain Non-Hodgkin lymphoma Bone Eye Non-Hodgkinlymphoma Bone Eye Burkitt lymphoma Ovary Connective tissue Burkitt lymphoma Liver & Bile duct Breast Naso-oropharynx Endocrine Other sites Other sites Percentage 14

13 Cancer of the cervix was the most common cancer in young women aged years old, comprising 12.5% of all cancers. The five most common cancers, in order, included the cervix, breast, Kaposi sarcoma, BCC and melanoma, with proportions of all cancers in this age group ranging between six percent for melanoma and 12.5% for the cervix (Figure 9). In young males in the same age group, leukemia remained the most common cancer, as in children. The five most common cancers in these males, in order, were leukemia, BCC, Kaposi sarcoma, non-hodgkin lymphoma and bone. The proportions of all cancers in this age group ranged between 6.8% for bone and 9.8% for leukemia. This is the only age group where Kaposi sarcoma ranks in the five most common cancers. Figure 9: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, years Males ( n = 1853) Females (n = 2 368) Leukaemia Cervix BCC Breast Kaposi Sarcoma Kaposi Sarcoma Non-Hodgkin lymphoma BCC Bone Melanoma Hodgkin lymphoma Non-Hodgkin lymphoma Melanoma Hodgkin lymphoma Testis Thyroid Liver & Bile duct Leukaemia Connective tissue Ovary Other sites Other sites Percentage Cancer of the cervix was the most common and comprised one quarter of all cancers in females aged years. Cancer of the cervix, the breast (the second most common cancer) and BCC together comprised about two-thirds of all female cancers in this age category (Figure 10). Included in the five most common cancers were melanoma and cancer of the oesophagus, each comprising 2.5% of all cancers in this age category. Breast and cervix cancer remained the most common cancers in females aged years old comprising 19.7% and 18.6% of all cancers in this age group respectively (Figure 11). In women 65 years and older, cancers of the breast and the cervix, comprising 16.1% and 11.51% respectively were second and third most common cancers to BCC, which comprised 20.9% of all cancers in this age group (Figure 12). Figure 10: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, years Males (n = ) Females (n = ) BCC Cervix Oesophagus Breast Lung BCC SCC of skin Melanoma Colorectal Melanoma Oesophagus Ovary Karposi sarcoma Colorectal Prostate SCC of skin Nod-Hodgkin lymphoma Stomach Other sites Lung Non-Hodgkin lymphoma Other sites Percentage 15

14 Figure 11: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, years Males (n = ) Females (n = ) BCC Prostate Lung Oesophagus SCC of skin Colorectal Bladder Larynx Stomach Melanoma Other sites Breast Cervix BCC Oesophagus Uterus SCC of skin Lung Colorectal Ovary Melanoma Other sites Percentage BCC was the most common cancer in males, comprising about one quarter of all cancers in age groups older than 30 years. Although prostate cancer was the eighth most common cancer at ages 30 to 54, at ages 55 years and older, it became the second most common cancer comprising 15.2% in young elderly men (55-64 years) and 22.1% in elderly men (65+) (Figures 10-12). Cancer of the prostate together with non-melanoma skin cancers comprised more than half of all cancers in men 65 years and older. Figure 12: Percentage distribution of 10 most common cancers by sex, 1998 and 1999, 65+ years Males (n = ) Females (n = ) BCC BCC Prostate Breast SCC of skin Cervix Lung SCC of skin Colorectal Colorectal Bladder Uterus Oesophagus Oesophagus Stomach Lung Melanoma Ovary Larynx Melanoma Other sites Other sites Percentage 16

15 3.4 Incidence of cancer in 1998 and 1999 This section presents the incidence of cancer and the ranking of leading cancers. This ranking is based on age standardised rates rather than on the actual number or proportions of cancers on which the common cancers discussed in section above were based. Basal cell carcinoma and SCC of skin are excluded from the ranking as these occur most commonly with very high incidence rates, particularly in Whites, and therefore tend to overshadow all other cancers. Since the registry reports cancers by site, cancers whose primary site is not known or for which there is no indication of the primary site particularly in the case of cancers that have metastasized to other sites are classified as PSU (i.e. primary site unknown). These are also excluded from the ranking. Table 4 presents a summary of the five leading cancers diagnosed in 1998 and 1999 for each population group in males and females. In 1999, the risk of developing cancer in South African females between ages 0-74 years was 1 in 6 females (1 in 5 females when adjusted for under-reporting). The ASR for cancer in females was per (95% CI= ). Cancers of the breast, cervix, colorectal, oesophagus and uterus were, in order, the five leading cancers in females. The risk of developing cancer in a male s lifetime in 1999 was 1 in 5 (1 in 4 when adjusted for under-reporting). Cancer of the prostate, lung, oesophagus, colorectal and bladder were, in order, the leading cancers with all cancers in males having an ASR of per (95% CI= ). Overall cancer rates observed in 1999 are lower than those reported for 1997 and The low rates observed in 1999 compared to the previous years cannot be explained, a number of factors could be attributed. These might inlcude under-reporting, or this might be reflecting real trends in cancer status. The changes in service delivery could not be ruled out but cancer time trends will be closely monitored. In addition, it is important to note that the NCR s previous cancer reports were reporting the upper confidence limits (UCL) of the ASR and therefore, for comparison purposes with previous reports, one should use UCLs from the tables at the back of this report. Table 4: Summary rates for the leading five cancers by race group and sex, 1998 and Pop / Sex Cancer ASR LR Cancer ASR LR Asian Female Breast Breast Cervix Cervix Uterus Colorectal Colorectal Uterus Stomach Ovary All All Asian Male Prostate Prostate Stomach Colorectal Lung Lung Colorectal Stomach Leukaemia Bladder All All Black Female Cervix Cervix Breast Breast Oesophagus Oesophagus Uterus Uterus Ovary Ovary All All Black Male Prostate Prostate Oesophagus Oesophagus Lung Lung Larynx Larynx Stomach Colorectal All All

16 Coloured Female Breast Breast Cervix Cervix Colorectal Colorectal Lung Lung Stomach Uterus All All Coloured Male Prostate Prostate Lung Lung Colorectal Stomach Stomach Colorectal Oesophagus Bladder All All White Female Breast Breast Melanoma Colorectal Colorectal Melanoma Cervix Cervix Ovary Ovary All All White Male Prostate Prostate Colorectal Colorectal Bladder Bladder Lung Melanoma Melanoma Lung All All All Females Cervix Breast Breast Cervix Colorectal Colorectal Oesophagus Oesophagus Ovary Uterus All All All Males Prostate Prostate Lung Lung Oesophagus Oesophagus Colorectal Colorectal Bladder Bladder All All ASR Age standardised incidence rate per (World standard population) LR Lifetime risk (0-74 years) of developing a cancer expressed as 1 in X number of people Please note: ASR for all males and females excludes BCC and SCC of skin Ranking excludes BCC, SCC of the skin, PSU and ill defined sites 18

17 3.5 Cancer by site This section presents a brief discussion of the five leading cancers in males and females. Included as well are sites that are known to have shown increases in incidence rates as a result of their association with HIV and AIDS or are highly prevalent in South African populations for example melanoma and non-melanoma skin cancers. These include Kaposi sarcoma and Non-Hodgkin lymphoma Cancer of the Bladder Cigarette smoking is the most important risk factor for bladder cancer and shows a linear increasing relationship with the number of cigarettes smoked per day and the duration of smoking. In developed countries it accounts for 65% of all bladder cancer cases in men and 30% of female bladder cancer cases (Parkin, Ferlay et al., 2003; Stewart and Kleihues, 2003). Epidemiological studies establishing a relationship between smoking and bladder cancer and controlling for confounders, showed that, relative to never-smokers, the strength of association (OR) ranged between 1.4 (CI= ) Table 5: Summary statistics for bladder cancer, 1998 and 1999 Pop / Sex N(Obs) N(Adj) Percent Crude ASR 95%LCL 95%UCL Cumrisk LR Females, 1998 Asian Black Coloured White Total Males, 1998 Asian Black Coloured White Total Females, 1999 Asian Black Coloured White Total Males, 1999 Asian Black Coloured White Total N(Obs) Number of cases observed N(Adj) Observed cases adjusted for unknown population group Percent Percentage of all site cancers Crude Number of cases / population per ASR Age standardised incidence rate per (World standard population) 95%LCL 95% Lower con dence limit for ASR 95%UCL 95% Upper con dence limit for ASR Cumrisk Cumulative lifetime incidence risk (0-74 years) LR Lifetime risk (0-74 years) of developing a cancer expressed as 1 in X number of people Please note: Ranking excludes BCC, SCC of the skin, PSU and ill de ned sites 19

18 in males smoking 15g tobacco per day and 6.6 (CI= ) for current smokers. The strength of association depended on histology type, with the risk higher for Transitional cell carcinoma (TCC), (OR = 9.1) than other histologies (OR = 4.4), duration and magnitude of smoking relative to non-smokers. Relative to neversmokers, smokers smoking less than 20 cigarettes per day had a relative risk of 5.4 compared to 7.6 for those having smoked 20 or more years. Higher risk (OR = 16.5) was observed among smokers who had smoked more than 40 years (Vizcaino et al., 1994; Bedwani et al., 1997; Parkin, Ferlay et al., 2003). Infection with Schistosoma haematobium (urinary bilharziasis) is reported to be a major risk factor in areas with high prevalence and, possibly, urinary tract infections in women (Parkin, Ferlay et al., 2003; Stewart and Kleihues, 2003). Diets rich in vitamin A and carotenoids have been associated with decreased risk of bladder cancer. Some other known risk factors for bladder cancers, which have not been investigated in Africa, are related to occupation. These include rubber and dyestuff industries, exposure to aromatic amines, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, formaldehyde, asbestos, leather manufacturers and painters (Parkin, Ferlay et al., 2003). Numbers and incidence A total of 1028 and 1005 bladder cancer cases were reported in males in 1998 and 1999 respectively. These comprised about 3.5% of all cancers reported in males. Bladder cancer was the fifth leading cancer in both 1998 and The crude rate in males was 4.7 per and the ASR was 8 per (Table 5). Males were at higher risk of developing bladder cancer than females, as their chances were three times that observed in women. The risk of developing bladder cancer increased with age. Incidence rates greater than 49 per were observed in men 65 years and older (Figure 13). In 1998, one in 98 men and in 1999, one in 104 men aged 0 74 years were at risk of developing bladder cancer. In women, a total of 426 and 395 bladder cancers were reported in 1998 and 1999 respectively and these comprised 1.4% of all female cancers reported. Bladder cancer was the 11th leading cancer in women in the two years, with a crude rate on average of 1.8 per and an ASR of 2.5 per At ages 65 years and older, ASIRs of 12 per and higher were observed in elderly women. The lifetime risk (ages 0-74 years) of developing bladder cancer in women was 1 in 353 and 1 in 362 in 1998 and 1999 respectively. Figure 13: Age specific incidence rates for bladder cancer by population group, Bladder, Females 50 ASIR / Age Group AF BF CF WF 300 Bladder, Males 250 ASIR / Age Group AM BM CM WM 20

19 Population variation Bladder cancer was the third leading cancer in white males, comprising 4.5% of all white male cancers in the two years. White males comprised 68% and 71% of all bladder cancer cases reported in 1998 and 1999 respectively. The lifetime risk of developing bladder cancer in white males was 1 in 35 with the highest incidence rate of 23.7 per In both coloured and Asian males, bladder cancer ranked the sixth and fifth leading cancers in 1998 and 1999 respectively. Coloured males were at higher risk of developing bladder cancer than Asian males, with an ASR of 12 per compared to 7.4 per in 1998 and 10.5 in 1999 reported among Asian males (Table 5). Bladder cancer comprised on average 1.5% of all cancers reported in black men and had the lowest incidence rates of 2.3 per and about 1 per in the two consecutive years (Table 5). In 1999, the incidence rate in black men was about 16 times lower than that observed in white men. The bladder cancer incidence pattern in females was similar to that observed in males. It comprised on average about 1.7% of all cancers in white females. White women also had the highest incidence rates of 5.2 per and 6.3 per in the two consecutive years compared to other population groups. In 1998 and 1999, bladder cancer ranked the ninth and eighth leading cancer in white women and comprised 47.6% and 61.4% of all bladder cancer cases respectively. Coloured females had the second highest ASR of 2.8 per , with the lowest rates reported among black females. The incidence rate for bladder cancer in black women was eight times lower than that observed in white women. International comparison Worldwide, cancer of the bladder is the ninth common cancer, with about new cases reported per year (Stewart and Kleihues, 2003). In 2000, about new bladder cancer cases were reported from Africa, with high incidence rates found in North Africa (Parkin, Ferlay et al., 2003). In 1999, bladder cancer incidence rates in White and Coloured South African men were among the highest rates reported worldwide, particularly in developed countries (Figure 14). Incidence rates among South African Asians are double those reported in men in India (Bombay). Rates among South African Black men are among the lowest rates reported. Parkin, Ferlay et al. (2003) argue that the limitations in comparability of bladder cancer include different practices concerning cytoscopy, biopsy of lesions, the extent of histological examination of biopsy material and the classification of malignant, non-invasive tumours. Incidence rates for bladder cancer in black women in Zimbabwe (Harare) and South African white women were among the highest rates reported in women worldwide. Rates in South African Asian women and women in India (Bombay) compare well. It is not clear whether the low incidence rates observed in Uganda, South Africa (Black men and women) and The Gambia are a true reflection of the status of bladder cancer or are due to the limitations mentioned by Parkin, Ferlay et al., (2003). Figure 14: Bladder cancer ASR per for selected populations Bladder - Females Age standardised rates per Zimbabwe (Harare) 8.3 SA, White 6.3 USA, SEER (White) 6.2 UK, England 6.1 Mali (Bamako) 5.8 Australia (Tasmania) 4.6 USA, SEER (Black) 4.2 SA, Coloured 2.8 Brazil (Goiania) 2.7 Algeria (Algiers) 2.3 SA, Asian 1.8 India (Bombay) 1.3 Uganda (Kyadondo) 1.2 SA, Black 0.8 The Gambia Bladder - Males Age standardised rates (per ) SA, White 23.7 USA, SEER (White) 23.3 UK, England 22.3 Australia (Tasmania) 19.9 SA, Coloured 12.5 USA, SEER (Black) 11.3 Mali (Bamako) 11.3 Brazil (Goiania) 11.2 Algeria (Algiers) 10.8 SA, Asian 10.5 Zimbabwe (Harare) 8.3 India (Bombay) 4.6 Uganda (Kyadondo) 2.9 SA, Black 1.5 The Gambia (Data source: Parkin, Whelan et al., 2002) 21

20 3.5.2 Cancer of the Cervix Infection with high-risk oncogenic human papilloma virus (HPV) types (including types 16, 18, 31, 33, 39, 45, 52 and 35) is known to be a necessary cause of cervical cancer (IARC, 1995; Walboomers et al., 1999; Santos et al., 2001; Bosch et al., 2002; Munoz et al., 2003; Monsonego et al., 2004). The worldwide prevalence of HPV in cervical carcinomas is reported to be 99.7% (Walboomers et al., 1999). Some endogenous or exogenous factors are believed to act in conjunction with HPV infection to cause invasive cancer. Other risk factors known to be strongly associated with invasive cervical cancer include low social class, as well as sexual behaviour such as the lifetime number of sexual partners, and early age at first intercourse (Green et al., 2003). Smoking had been associated with cervical cancer. Evidence on the relationship between progestogen-only contraceptives and cervical cancer is, however, unclear. In 1993 the cancer of the cervix was declared an AIDS defining condition because of its association with HIV and AIDS (Serraino, et al., 1999; Frisch et al., 2000). Data in Africa has been slow in demonstrating this association and only lately that studies in Africa were able to demonstrate this association. There is to date good data showing an increased incidence of invasive cervical cancer to HIV epidemic. Since 1960, a moderate increase in cervical cancer was reported for all age groups in Uganda (Parkin, Ferlay, et al., 2003). In a case-control study in Johannesburg Sitas et al., (2000), showed a slight association between HIV and cancer of the cervix (OR=1.6, 95% CI ), but a former study appeared to contradict this finding (Sitas, et al., 1997). Similar relative risk was reported in Uganda and in Rwanda (Newton et al., 1995; 1996; 2001). However, some studies have demonstrated an association between HIV and the increased prevalence of human papilloma virus (HPV) and cervical intraepithelial neoplasia (CIN) (Thomas, 2001; Mbulaiteye, et al., 2003). Table 6: Summary statistics for cervix cancer, 1998 and 1999 Pop / Sex N(Obs) N(Adj) Percent Crude ASR 95%LCL 95%UCL Cumrisk LR Females, 1998 Asian Black Coloured White Total Females, 1999 Asian Black Coloured White Total N(Obs) N(Adj) Percent Number of cases observed Observed cases adjusted for unknown population group Percentage of all site cancers Crude Number of cases / population per ASR 95%LCL 95%UCL Cumrisk LR Please note: Age standardised incidence rate per (World standard population) 95% Lower con dence limit for ASR 95% Upper con dence limit for ASR Cumulative lifetime incidence risk (0-74 years) Lifetime risk (0-74 years) of developing a cancer expressed as 1 in X number of people Ranking excludes BCC, SCC of the skin, PSU and ill de ned sites 22