AN ESCALATING THYROID CANCER EPIDEMIC IN CANADA 1970 2012 Dawnelle Topstad MD FRCSC MPH Candidate James A. Dickinson MBBS PhD CCFP FRACGP
No Disclosures
INTRODUCTION + Thyroid cancer incidence rate while mortality unchanged + Greater increase in females than males 1,2 + In Canada, thyroid cancer is 5 th most common in females 3 + Thyroid cancer epidemic caused by changing risk factors OR over-diagnosis
METHODS National Data Analysis for Canada o National Cancer Incidence Reporting System (NCIRS) * o Canadian Causes of Death Tables 4 o Recently Canadian Cancer Registry 5 ASIR using 1991 census population structure * available from Public Health Agency of Canada DAWNELLE TOPSTAD MD FRCSC
CANADA
RATE / 100 000 AGE STANDARDIZED INCIDENCE & MORTALITY RATES for THYROID CANCER 1970 2012 35 30 FEMALES-INCIDENCE MALES-INCIDENCE MORTALITY 25 20 15 10 5 0 1970 1975 1980 1985 1990 1995 2000 2005 2010 YEAR
INCIDENCE RATE / 100 000 1970 2012 AGE STANDARDIZED INCIDENCE RATES for THYROID CANCER in FEMALES by PROVINCE 35 30 ON QC AB BC 25 20 15 10 5 0 1970 1975 1980 1985 1990 1995 2000 2005 2010 YEAR
INCIDENCE RATE / 100 000 1970 2012 AGE STANDARDIZED INCIDENCE RATES for THYROID CANCER in MALES by PROVINCE 35 30 25 ON QC AB BC 20 15 10 5 0 1970 1975 1980 1985 1990 1995 2000 2005 2010 YEAR
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-55 55-59 60-64 65-69 70-74 75-79 80-84 >85 INCIDENCE RATE / 100 000 1972, 1992, 2012 AGE SPECIFIC INCIDENCE RATES for THYROID CANCER by GENDER 70 60 50 40 1972 Male 1992 Male 2012 Male 1972 Female 1992 Female 2012 Female 30 20 10 0 AGE BY YEAR
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 >85 INCIDENCE RATE / 100 000 1972, 1992, 2012 AGE SPECIFIC INCIDENCE RATES for THYROID CANCER in FEMALES by PROVINCE 70 60 50 40 1972 BC 1992 BC 2012 BC 1972 ON 1992 ON 2012 ON 30 20 10 0 AGE BY YEARS
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-55 55-59 60-64 65-69 70-74 75-79 80-84 >85 INCIDENCE RATE / 100 000 1972, 1992, 2012 AGE SPECIFIC INCIDENCE RATES for THYROID CANCER in MALES by PROVINCE 70 60 50 40 1972 BC 1992 BC 2012 BC 1972 ON 1992 ON 2012 ON 30 20 10 0 AGE IN YEARS
CONCLUSIONS + Thyroid cancer incidence increasing since 1990 + Mortality rate is unchanged + Incidence rates increasing more rapidly in females + Incidence rate varies widely by province + Rapid increase in 40-65 year females
IMPLICATIONS WHY EPIDEMIC? + Risk factors o o o Increase somatic mutation Increasing exposure to radiation Iodine deficiency or excess +Access to healthcare o Universal healthcare in all Canadian provinces + Over-diagnosis
RECOMMENDATIONS 1. Raise awareness among medical personnel & patients 2. Identify small subset of patients who have potentially fatal thyroid cancer 3. Promote observation and less aggressive treatment for small thyroid cancers
ACKNOWLEDGMENTS + Special thanks to Public Health Agency of Canada for providing data from the National Cancer Incidence Reporting System database + Canada Cancer Registry + Canadian Task Force on Preventive Health Care & University of Alberta for funding
REFERENCES 1. Davies L, Welch HG. Increasing incidence of thyroid cancer in the United States, 1973-2002. JAMA 2006;295:2164-7. 2. Kweon SS, Shin MH, Chung IJ, Kim YJ, Choi JS. Thyroid cancer is the most common cancer in women, based on the data from population-based cancer registries, South Korea. Jpn J Clin Oncol 2013;43:1039-46. 3. Predictions of the future of cancer in Canada. Ottawa, Ontario: Canadian Cancer Statistics Special Topic, 2015. 4. Causes of Death, 1970 to 1999: Provinces by Sex and Canada by Sex and Age. Ottawa, Ontario: Statistics Canada. (Catalogue no. 84F0208XPB, 84-208, 84-203, 82-003S11). 5. CANSIM (database). Table 051-0005. Estimates of population, Canada, provinces, and territories. Table 102-0522 - Deaths, by cause, Chapter II: Neoplasms, age group and sex, Canada. Table 103-0550 New cases of primary cancer (based on the August 2015 CCR tabulation file), by cancer type, age group and sex, Canada, provinces and territories. Table 103-0553/4 New cases and 1991/2011 age-standardized rate for primary cancer (based on the August 2015 CCR tabulation file), by cancer type and sex, Canada, provinces and territories. Ottawa, Ontario: Statistics Canada.