1. Cervical cancer among Asian subgroups in California, 1990-2004 Janet Bates, MD MPH California Cancer Registry NAACCR Annual Meeting Denver, Colorado June 10, 2008

2. Background National cancer statistics show lower overall cancer rates among Asians in the US Asians have wide variability in countries of origin, immigration history, culture, language, education and SES that influence cancer risk Aggregated cancer statistics for Asians mask important differences among subgroups Limited national cancer data available on Asian subgroups

3. Asians in California California has largest Asian population of any state 3.7 million Asians = 12% of state population 90% of California Asian population comprised of 6 subgroups: Chinese, Filipino, Japanese, Korean, South Asian, and Vietnamese

4. Study purpose To describe patterns of cervical cancer incidence, mortality, and survival among 6 major Asian subgroups in California

5. Methods Cervical cancer cases diagnosed among California residents 1990-2004 Included all 6 Asian subgroups and non- Hispanic whites (NHW) Variables: –Age (<40, 40-64, 65+ years) –SES quintile (composite census-based measure*) –Stage (local, regional, distant, unknown) –Surgery (none, local, hysterectomy, other) –Radiation (none, any) –Chemotherapy (none, any) *Yost K et al, Cancer Causes & Control, 2001

6. Methods Cervical cancer incidence rates and trends calculated using SEERstat Cervical cancer survival probabilities (5 and 10 year) calculated using Kaplan-Meier method Multivariate evaluation of survival calculated using Cox proportional hazards modeling, adjusted for stage, age, SES, and treatment factors

7. Results

8. Demographic characteristics: age and SES ChineseFilipinoJapan.KoreanS. AsianViet.NHW N4857471983098848410,879 %%%% Age (yrs) **** <4017.118.224.814.918.26.829.9 40-6447.458.051.557.056.868.048.4 65+35.523.823.728.225.025.221.7 SES quintile **** 1 (low)11.617.08.119.417.120.012.2 5 (high)29.913.025.321.421.613.621.2 * P for comparison with NHW is significant at < 0.05

9. Clinical characteristics: stage distribution ChineseFilipinoJapan.KoreanS. AsianViet.NHW N4857471983098848410,879 %%%% Stage * ** Local48.045.951.046.044.355.053.7 Regional37.539.936.938.533.037.631.3 Distant6.810.48.69.715.94.610.9 Unknown7.63.83.55.86.82.94.1 * P for comparison with NHW is significant at < 0.05

10. Clinical characteristics: stage distribution ChineseFilipinoJapan.KoreanS. AsianViet.NHW N4857471983098848410,879 %%%% Stage * ** Local48.045.951.046.044.355.053.7 Regional37.539.936.938.533.037.631.3 Distant6.810.48.69.715.94.610.9 Unknown7.63.83.55.86.82.94.1 * P for comparison with NHW is significant at < 0.05 Lowest proportion of cases diagnosed at local stage were found among South Asian, Filipino, and Korean women; stage distribution among South Asian women not significantly different from NHW

11. Cervical cancer incidence trends: 1990-2004

12. Vietnamese had highest incidence throughout period, as well as most dramatic decline

13. Cervical cancer incidence trends: 1990-2004 …followed by Korean, then Filipino women

14. Cervical cancer incidence trends: 1990-2004 Chinese women and NHW had comparable rates in 1990-1992…

15. Cervical cancer incidence trends: 1990-2004 …but by 2002-2004 incidence rates were lower among Chinese women NHW Chinese

16. Cervical cancer incidence trends: 1990-2004 Rates among Japanese and South Asian women also declined, but trend not statistically significant Japanese South Asian

17. Unadjusted cause-specific 5- and 10-year cervical cancer survival Survival probability (%) (95% Confidence Interval) ChineseFilipinoJapaneseKoreanS. AsianViet.NHW 5-year78.6 (74.4, 82.2) 79.0 (75.9, 81.9) 72.3 (64.9, 78.4) 85.7 (80.9, 89.6) 85.8 (75.1, 92.2) 0.79 (0.64, 1.00) 77.5 (76.7, 78.3) 10-year77.2 (72.9, 81.0) 74.8 (71.2, 78.0) 69.5 (61.7, 76.1) 82.5 (77.1, 86.7) 85.8 (75.1, 92.2) 79.7 (75.4, 83.3) 75.4 (74.6, 76.3)

18. Unadjusted cause-specific cervical cancer survival

19. Clinical characteristics: stage distribution ChineseFilipinoJapan.KoreanS. AsianViet.NHW N4857471983098848410,879 %%%% Stage * ** Local48.045.951.046.044.355.053.7 Regional37.539.936.938.533.037.631.3 Distant6.810.48.69.715.94.610.9 Unknown7.63.83.55.86.82.94.1 * P for comparison with NHW is significant at < 0.05 Lowest proportion of cases diagnosed at local stage were found among South Asian, Filipino, and Korean women; stage distribution among South Asian women not significantly different from NHW

20. Risk of death due to cervical cancer among Asian subgroups Hazard Ratio (95% Confidence Interval) ChineseFilipinoJapaneseKoreanS. AsianViet. Race only 0.94 (0.78, 1.15) 0.97 (0.83, 1.13) 1.28 (0.97, 1.69) 0.61 (0.45, 0.81) 0.57 (0.32, 1.04) 0.79 (0.64, 1.00) Referent group is Non-Hispanic Whites

21. Risk of death due to cervical cancer among Asian subgroups Hazard Ratio (95% Confidence Interval) ChineseFilipinoJapaneseKoreanS. AsianViet. Race only 0.94 (0.78, 1.15) 0.97 (0.83, 1.13) 1.28 (0.97, 1.69) 0.61 (0.45, 0.81) 0.57 (0.32, 1.04) 0.79 (0.64, 1.00) Stage0.97 (0.79, 1.18) 0.84 (0.72, 0.98) 1.19 (0.90, 1.56) 0.49 (0.37, 0.66) 0.37 (0.20, 0.66) 0.83 (0.676, 1.03) Referent group is non-Hispanic whites

22. Risk of death due to cervical cancer among Asian subgroups Hazard Ratio (95% Confidence Interval) ChineseFilipinoJapaneseKoreanS. AsianViet. Race only 0.94 (0.78, 1.15) 0.97 (0.83, 1.13) 1.28 (0.97, 1.69) 0.61 (0.45, 0.81) 0.57 (0.32, 1.04) 0.79 (0.64, 1.00) Stage0.97 (0.79, 1.18) 0.84 (0.72, 0.98) 1.19 (0.90, 1.56) 0.49 (0.37, 0.66) 0.37 (0.20, 0.66) 0.83 (0.676, 1.03) Stage, age 0.89 (0.72, 1.09) 0.82 (0.70, 0.95) 1.15 (0.87, 1.52) 0.47 (0.35, 0.62) 0.34 (0.19, 0.62) 0.79 (0.64, 0.98) Referent group is non-Hispanic whites

23. Risk of death due to cervical cancer among Asian subgroups ChineseFilipinoJapaneseKoreanS. AsianViet. Race only 0.94 (0.78, 1.15) 0.97 (0.83, 1.13) 1.28 (0.97, 1.69) 0.61 (0.45, 0.81) 0.57 (0.32, 1.04) 0.79 (0.64, 1.00) Stage0.97 (0.79, 1.18) 0.84 (0.72, 0.98) 1.19 (0.90, 1.56) 0.49 (0.37, 0.66) 0.37 (0.20, 0.66) 0.83 (0.676, 1.03) Stage, age 0.89 (0.72, 1.09) 0.82 (0.70, 0.95) 1.15 (0.87, 1.52) 0.47 (0.35, 0.62) 0.34 (0.19, 0.62) 0.79 (0.64, 0.98) Stage, age, Rx, SES 0.83 (0.68, 1.02) 0.78 (0.67, 0.91) 1.13 (0.86, 1.50) 0.42 (0.31, 0.57) 0.31 (0.17, 0.56) 0.77 (0.62, 0.96) Referent group is non-Hispanic whites

24. Discussion Higher incidence among Vietnamese, Korean, Filipino women mirror international patterns South Asian rates relatively low despite high rates in countries of origin

25. Discussion Variability in cervical cancer incidence is largely attributed to screening Expect populations with low screening to have higher incidence Examined cervical cancer screening survey data from the California Health Interview Survey (CHIS)

26. Percent pap test in past 3 years by Asian subgroup, California Source: California Health Interview Survey 2003

27. Percent pap test in past 3 years and cervical cancer incidence by Asian subgroup, California Source: California Health Interview Survey 2003

28. Limitations Limited number of cases in some subgroups Misclassification of race is possible Risk factor data (HPV subtypes, smoking, diet, co-morbidities, immigration data, etc.) not available

29. Summary Distinct variations among subgroups in patterns of cervical cancer incidence and survival Practice of aggregating statistics for Asians masks these differences Public health programs targeting cervical cancer screening and prevention must take these differences into account

30. Summary Lower risk of cervical cancer death among Vietnamese, Korean, Filipino, and South Asian women Few studies on this Further evaluation of reasons for this apparent survival advantage is needed

31. Acknowledgements Co-authors: Brenda Hofer, Arti Parikh- Patel CDC Cancer supplement coordinators: Meg Watson, Mona Saraiya CCR research and surveillance program staff: Mark Allen, Allyn Fernandez Ami, Sandy Kwong