TARGETS To reduce the age-standardised mortality rate from cervical cancer in all New Zealand women to 3.5 per or less by the year 2005.

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1 Cervical Cancer Key points Annually, around 85 women die from, and 230 women are registered with, cervical cancer. The decline in both incidence and mortality rates for cervical cancer has accelerated since 1991 and is most likely due to improvements in cervical screening since the mid-1980s. Based on current trends, the cervical cancer incidence and mortality targets for the total population are likely to be achieved by the year The Mäori women s cervical cancer incidence target for the year 2005 could possibly be achieved if the reductions that have occurred since 1991 continue. By the end of December 1997, 83 percent of eligible women (20 69 years) were enrolled on the National Cervical Screening Programme and had had a smear in the previous five years. The cervical screening coverage target of 85 percent of eligible women being enrolled in the National Cervical Screening Programme and having had a smear in the previous five years, is likely to be achieved. TARGETS To reduce the age-standardised mortality rate from cervical cancer in all New Zealand women to 3.5 per or less by the year To reduce the age-standardised incidence rate of cervical cancer in all New Zealand women to 8.6 per or less by the year To reduce the proportion of invasive cervical cancers beyond stage 1 at the time of detection to 30 percent or less by the year To reduce the age-standardised mortality rate from cervical cancer in Mäori women to 9.4 per or less by the year 2000 and to 6.6 per or less by To reduce the age-standardised incidence rate of cervical cancer in Mäori women to 11.0 per or less by the year derivation The cervical screening targets are included in the National Cervical Screening Programme Policy (Ministry of Health 1996e), and update targets presented in the 1991 and 1993 Government Policy for Cervical Screening (Department of Health 1991; Ministry of Health 1993), and targets from the Public Health Commission s publication Cervical Cancer: The Public Health Commission s advice to the Minister of Health (PHC 1994c). The cervical cancer incidence and mortality targets for Mäori women are also referenced in the paper Rangatahi Sexual Wellbeing and Reproductive Health (Ministry of Health 1997m). 187

2 Indicators Age-standardised cervical cancer mortality rate for all women. Age-standardised cervical cancer mortality rate for Mäori women. Age-standardised cervical cancer incidence rate for all women. Age-standardised cervical cancer incidence rate for Mäori women. Proportion of invasive cervical cancer detected at stage 2 or 3 of the disease. Data source Cancer mortality data and cancer registration data (stored as part of the National Minimum Dataset) from the NZHIS. The latest data available on cervical cancer registrations and mortality are provisional for 1995 and 1996 respectively. Health impact There are two main types of cervical cancer: squamous cell carcinoma and adenocarcinoma. Squamous cell carcinoma constitutes more than 85 percent of all cervical cancers (Llewellyn- Jones 1996). Most tumours arise after the development of a precursor pre-malignant condition (cervical intraepithelial neoplasia), so that screening for the precursor condition and appropriate treatment has become the main way to reduce mortality from this disease. Annually, around 85 women die from, and 230 women are registered with, cervical cancer (calculated from the latest five years of data). Based on cervical cancer incidence rates , approximately one in 91 New Zealand women (1.1 percent) can expect to develop cervical cancer between birth and 75 years of age. The incidence rates of cervical cancer are highest in women aged years and death rates are highest for women 65 year or older. In the UK and Australia both mortality and incidence have increased for younger women, and it is likely that this is a cohort effect and that these women will remain at increased risk for the rest of their lives (Chamberlain and Moss 1995). In New Zealand, women of recent generations have an increased risk of cervical cancer (Cox and Skegg 1986), and this most likely reflects changes in sexual behaviour in recent decades. Cox and Skegg (1992) have projected that even with improved cervical screening in New Zealand, only small reductions may be evident in both mortality and incidence. However, without improvements in cervical screening the number of women developing cervical cancer could double due to the ageing of recent generations at higher risk of the disease. Risk factors Studies over many years have found age at first intercourse and total number of sexual partners are strongly linked to an increased risk of cancer of the cervix (Rotkin 1973; Brinton 1992; Bornstein et al 1995). An associated risk factor is having a male sexual partner who has had multiple previous sexual partners (Skegg et al 1982; Brinton et al 1989; Kjaer et al 1991). Indeed, a sexually transmitted agent has been implicated and a causal association has been found between human papillomavirus (HPV) infections and cervical cancer, particularly with the subtypes HPV 16 and 18 (Munoz and Bosch 1992). 188 Progress on Health Outcome s 1998

3 There is evidence that tobacco smoking increases the risk for cervical cancer. The risk is reported to increase with the amount and duration of tobacco consumption and inversely with the age at which smoking began (Gram et al 1992). Even after adjusting for confounding factors, smokers have been reported to have several times the risk compared to non-smokers, depending on the quantity and duration of smoking (Slattery et al 1989). Smoking may result in local immunosuppression of the cervical epithelium, thereby contributing to the development of cervical neoplasia (Barton et al 1988). Prolonged oral contraceptive use may also be associated with an increased risk of cervical cancer (Brinton 1991; WHO Collaborative Study 1993). Progress toward the target Incidence Between 1991 and 1995 an average of 230 women were registered annually with cervical cancer, of whom 16 percent were Mäori and 7 percent were Pacific women. In 1995, the latest year in which data are available, a total of 231 women were registered with cervical cancer. Figure 67: Cancer of the cervix incidence rate, by ethnicity, Age-standardised rate per Year Total Mäori Note: Rates are three-year rolling averages. For example, the 1994 data point represents the average annual rate for Source of data: New Zealand Health Information Service Most of the decrease in cervical cancer incidence rates has occurred since The agestandardised cervical cancer incidence rate for all women has decreased by around 20 percent since The incidence rate for Mäori women has declined by 35 percent since , yet at 22.4 per women (annual average ), it is still more than twice the national rate (Figure 67). 189

4 The incidence rate decline since 1990 and recent lower rates are most likely due to improvements in cervical screening since the mid-1980s. Mortality On average 85 women die from cervical cancer each year (based on rates for ). In 1996, 82 women died from cervical cancer; 22 were Mäori (27 percent) and three Pacific (4 percent). No ethnic-specific mortality statistics are available for 1995 due to changes in ethnicity coding in the latter part of the year (see Use of Ethnicity Data section). Figure 68: Cancer of the cervix mortality rate, Age-standardised rate per Year Note: Rates are three-year rolling averages. For example, the 1995 data point represents the average annual rate for Source of data: New Zealand Health Information Service The accelerated decline in mortality rates between 1991 and 1993 is most likely related to improvements in the level of cervical screening since the mid-1980s. The target was achieved in the time period (annual average rate); however, mortality rates appear to have reached a plateau since then (Figure 68). 190 Progress on Health Outcome s 1998

5 Figure 69: Cancer of the cervix mortality rate for Mäori (1996) compared to all women ( ) 12 Age-standardised rate per (Mäori) (Mäori) (Total) Average rate data only* Total Mäori Source of data: New Zealand Health Information Service * Caution must be used in interpreting information for Mäori women due to the low number of deaths and the availability of only one year of data using the new definition of ethnicity. In 1996, the age-standardised death rate for Mäori women, at 11.8 per women, was more than three times higher than the rate for all New Zealand women (Figure 69). However, this information needs to be interpreted with caution as in the past there has been considerable fluctuation in the Mäori rate due to the relatively small number of Mäori deaths from cervical cancer per year. Stage of disease Stage-of-disease data are one way of estimating the extent to which the screening programme is detecting disease at an appropriately early stage. In the early 1980s, approximately 45 percent of invasive cervical cancers were detected at stage 2 (regional or node involvement) or stage 3 (remote or diffuse metastases) of the disease, excluding cancers with no stage of disease reported. This proportion decreased to around 25 percent for No staging information is available for data from 1995 onwards. Assessment Data quality It is possible that some cervical cancer deaths and registrations are coded to other sites, such as the uterus (ICD9 182) or possibly the vagina (ICD9 184). In 1996, six cancers were classified as Malignant neoplasm of uterus, part unspecified ; some or all of these may have been cervical cancers. No studies have assessed the quality of cervical cancer data on the NZHIS cancer register or cervical cancer mortality data. 191

6 In September 1995 the methods used for recording ethnicity for mortality data changed from a system of biological classification to one of self-identification. This change has had a significant impact on the relative rates of mortality for Mäori and non-mäori, and makes comparisons of 1996 data with previous years misleading. For this reason, 1996 will be the start of a new time series for ethnic-specific data (see the section on Use of Ethnicity Data for more information). Stage-of-disease information has been poorly reported in the past few years. The Cancer Registry Act 1993 made registration of all cancers compulsory from 1 July The Act states that where information, such as stage of disease, is available it must be reported. The staging system used by the New Zealand Cancer Registry up until 1994 is not the same as the international (FIGO) classification system used for staging cancer. In 1997 problems were identified with the staging of cancers of the cervix for the year As a result, NZHIS withheld all cervical staging data until the issue could be investigated and resolved. A contributing factor was the lack of staging detail received by NZHIS for this period, which was reflected in the quality of data. Alternative stage-of-disease coding systems are being considered that may contribute to improving these data. Interpretation of trend Incidence A 17 percent decrease in cervical cancer incidence, from an average annual rate for of 10.4 per women, is required to reach the year 2005 target for all women. An average decrease of approximately 2 percent each year is required to the year If the trend of about a 5 percent annual decline continues, as it has since 1991, then the target for all women is likely to be achieved. The incidence rate for Mäori women for of 22.4 per needs to be reduced by 51 percent to reach the target of 11.0 per women or below by the year As the rate for Mäori women has declined 34 percent since 1991, it may be that if further improvements in cervical screening coverage for Mäori women can be achieved this target could be met. Mortality The average cervical cancer mortality rate for , at 3.7 per , requires a 5 percent decrease to meet the target in the year If the previous declining mortality trend continues, and provided women continue to have regular cervical smears, it is likely this target will be reached. The 1996 mortality rate for Mäori women needs to decline by 20 percent to reach the target in 2000, and 44 percent to reach the target in Until several years of mortality data are available for Mäori women using the new definition of ethnicity (see Use of Ethnicity Data section), progress toward the target for Mäori women cannot be accurately estimated. Stage distribution Stage-of-disease information are currently not available from NZHIS due to the poor quality of these data; therefore this target cannot be monitored at present. 192 Progress on Health Outcome s 1998

7 Strategies Strategies relating to cervical cancer are summarised at the end of this section. revision The target for the incidence rate among Mäori women will need to be revised to take account of the change in 1996 from a sole ethnic origin population to a Mäori ethnic group population. The mortality targets for Mäori women were revised to reflect the change in late 1995 in the way ethnicity information was collected. The interim revision was based on the increase in Mäori mortality attributed to the ethnicity coding change. As a result, the targets for Mäori mortality were increased by 25 percent. New targets will need to be developed once sufficient data from the new time series are available (see Use of Ethnicity Data section). The target level for stage distribution will be reset when these data are made available and the quality of these data has improved. Cervical cancer screening TARGET To increase the proportion of eligible women enrolled and screened in the previous five years to 85 percent or more by the year derivation The screening target was revised in The National Cervical Screening Programme Policy (Ministry of Health 1996e) and updates the process target presented in the 1991 and 1993 Government Policy for Cervical Screening (Department of Health 1991; Ministry of Health 1993) and the Public Health Commission s publication Cervical Cancer: The Public Health Commission s advice to the Minister of Health (PHC 1994c). The initial target was to increase the proportion of eligible women enrolled on the National Cervical Screening Register (NCSR) from 18 percent in 1992 to 75 percent in This target was exceeded in The revised target for 2000 increases the desired coverage rate for eligible women to 85 percent (or more), and adds the condition that these women should have been screened in the previous five years (Cervical Screening Advisory Committee, minutes of meeting June 1997). Indicator The proportion of eligible women (all women aged years) who are enrolled on the NCSR and who have had a smear in the previous five years. Data sources Enrolment information supplied by the NCSR (numerator) and 1996 Census population data from Statistics New Zealand (denominator) were used to calculate the proportion of eligible women enrolled in the National Cervical Screening Programme (NCSP) as at 20 December 193

8 1997. The denominator data were adjusted for women in the population who have had a hysterectomy: if the hysterectomy was for a benign condition and they had a normal smear history, they no longer require cervical smears. Health impact Screening for cervical cancer has never been evaluated through randomised trials, but evidence from ecological studies and analytical epidemiological investigations indicate that it has been highly effective in reducing incidence of invasive cancer in many countries (Day 1984; Hakama et al 1986). It is generally accepted that, in most cases, squamous cell cervical cancer is preceded by a pre-invasive stage which is likely to be asymptomatic and of variable duration, but could be detected by screening. If individuals are identified by screening, and treated early in this process, the progression to invasive disease can be prevented. Scandinavian countries have had considerable success in reducing mortality from cervical cancer and the extent of the reduction in mortality was related to the proportion of population coverage achieved by organised cervical screening programmes in these countries. Reductions in mortality ranged from percent depending on the level of cervical screening that had occurred in the targeted population (Laara et al 1987). The 1997 cervical screening guidelines recommend that all women who have ever had sexual intercourse should be offered a three-yearly cervical smear test between the ages of 20 and 70 years. If it is a woman s first smear, or there is a gap of five or more years since her last one, a second smear should be taken in a year s time. Women who have had a hysterectomy for a benign condition, with complete removal of histologically normal cervical epithelium and a normal smear history do not require further screening. Women who are immunocompromised may require more frequent screening. Women with signs and symptoms of cervical cancer should have a smear as part of the investigation and, regardless of the result, should be referred to a gynaecologist for assessment (Members of the Working Party on Cervical Screening 1998). International data suggest that women with the highest risk of cervical cancer are least likely to be screened (Williams 1992). Also, the majority of women who are diagnosed with invasive cervical cancer have either never had a cervical smear or have not had one for at least five years (Anderson et al 1988). Progress toward the target The NCSP began in 1990, and the proportion of eligible women enrolled on the register increased from 32 percent in 1993, to 69 percent at the end of 1995 and reached 85 percent by December As at the end of December 1997, 83 percent of eligible women were enrolled and had had a smear in the previous five years. Approximately 72 percent of eligible women had had a smear in the previous three years. 194 Progress on Health Outcome s 1998

9 Figure 70: Percentage of women aged years enrolled in the National Cervical Screening Programme, Percentage July 1993: Opt-off register Year Note: Unadjusted up to 1995 for women who have had a hysterectomy; population adjusted for hysterectomy from 1996 onwards. Source of data: National Cervical Screening Programme, Ministry of Health By the end of 1997 only a 3 percent increase was required to achieve the year 2000 target of 85 percent eligible women enrolled and having had a smear in the previous five years. Assessment Data quality Centralisation of the National Cervical Screening Register has improved the quality of data. Limitations of indicator Women being screened by the programme are unlikely to correspond to all women being screened in the population, as a small percentage of women will be having regular smears but have chosen not to be enrolled in the programme. Interpretation of trend Cervical screening enrolments have increased steadily in recent years. While the rate of new enrolments has slowed, the target is close to being met at present, and providing that women continue to have regular smears, it is likely the target for the year 2000 will be achieved. 195

10 Strategies National Cervical Screening Programme (NCSP) Protection of data Ethnicity data Safer sex programmes and tobacco control Cervical screening remains the most important strategy for preventing invasive cervical cancer. The NCSP was established in It is a population-based cancer screening programme, which provides national co-ordination of screening services managed and delivered at the local level. The NCSP target population is all women aged years who have ever had sexual intercourse and have not had a total hysterectomy for a benign condition. Priority groups are women who have never had a cervical smear, women aged over 35 years, and Mäori and Pacific women. The National Cervical Screening Register (NCSR) has been reconfigured into one centralised database with regional access from 14 local sites. The centralised NCSR allows for an increased volume of data, a reduction in duplication, improved tracking of women who move to different areas, and improved quality of smear test reading by providing laboratories with a woman s previous cytology and histology results. It also facilitates access data for national monitoring and evaluation. A third statistical report on the NCSR data has been produced (Ministry of Health 1998e). The Ministry of Health and the New Zealand Cancer Society established a working party to review the current Cervical Screening Recommendations. The review was published in 1998 in the New Zealand Medical Journal (Members of the Working Party on Cervical Screening 1998), and updated the 1991 working group recommendations (Paul et al 1991). The location of the national co-ordinator of the NCSP and the NCSR and its staff were transferred to the HFA in April 1998 from the Ministry of Health. The University of Otago was contracted by the Ministry of Health to scope an evaluation of the NCSP. Scoping of the evaluation was completed in April The Ministry of Health intends that a limited evaluation of the programme will commence in the latter part of The Health Act 1956 was amended in April 1993 to allow regulations to be made to provide additional protection to any class or classes of women. In May 1995 the Health (Cervical Screening (Kaitiaki)) Regulations were enacted to allow for the establishment of a National Kaitiaki Group. The Kaitiaki provides guardianship for wähine Mäori summary data stored on the NCSR and thus reassures wähine Mäori that their data are protected and will only be used for their benefit. A Pacific women s Data Management Group oversees the release of aggregated data for women identified as Pacific on the NCSR. Improvements have been made in the collection of ethnicity data for the NCSR. Both smear-takers and women themselves are given more information about why ethnicity data is collected and how it is used. Women have the opportunity to state or correct their ethnicity data on receipt of the initial letter from the NCSP, and the enrolment forms have been revised to make it easier for smear-takers to complete. Safer sex programmes may contribute to reducing the risk of cervical cancer over the longer term (see the section on STD). Since smoking also appears to be a risk factor, policies and strategies to reduce smoking rates, as outlined in the tobacco section, may also help. These measures, while potentially reducing the incidence of disease for future generations, will not affect the generations of women who have already been exposed to the causative agent and are unlikely to have any major impact on cervical cancer in the next 15 years (PHC 1994c). 196 Progress on Health Outcome s 1998

11 revision No revision appears necessary at present. Melanoma Key points The numbers of new melanoma registrations (approximately 1600 per year) and deaths (approximately 195 per year) are stable, especially in people aged less than 50 years. These favourable trends may reflect safer sun behaviours, especially in recent birth cohorts. Any trend towards earlier surgical intervention for melanomas remains to be confirmed. Outcome targets for melanoma incidence and mortality, developed by age/period/cohort modelling, may need to be reset. An intermediate outcome target for sunburn is being developed. TARGETS To reduce the age-standardised melanoma mortality rate to seven per or less among males, and three per or less among females by the year To reduce the age-standardised incidence rate of thick melanomas ( 1.5 mm) to six per or less by the year derivation The targets were set by the Public Health Commission in Melanoma: The Public Health Commission s advice to the Minister of Health (PHC 1994h), based on projections of the melanoma epidemic (Cox 1995). In 1997 these targets were converted from cumulative incidence to population incidence rates (for consistency with other targets), the target date was reset (to 2005), and the target for thick melanoma incidence was changed from a relative to an absolute rate (Ministry of Health 1997l). Indicators Melanoma mortality rate. Melanoma incidence (registration) rate by thickness. Data sources Mortality data are extracted from the NZHIS Mortality Database. The most recent data available are provisional for Incidence and thickness distribution data are extracted from the National Cancer Registry. The most recent data available are for