CANCER INCIDENCE AND CAUSE-SPECIFIC MORTALITY AMONG CANADIAN WOMEN WITH COSMETIC BREAST IMPLANTS NAACCR Annual Conference 2009 San Diego, California June 16-18, 2009 Lin Xie Surveillance Division Centre for Chronic Disease Prevention and Control Public Health Agency of Canada

2 Study Team Drs Jacques Brisson and Louis Latulippe - Laval University, Quebec Dr. Eric J. Holowaty, Cancer Care Ontario & University of Toronto, Ontario Dr. Paul J. Villeneuve, University of Toronto Drs. Yang Mao and Anne-Marie Ugnat, and Lin Xie - Public Health Agency of Canada

3 Background The demand for cosmetic breast augmentation has increased in recent years. An estimated 100,000 to 200,000 women in Canada have breast implants, approximately 80% for cosmetic breast augmentation and 20% for cosmetic reconstruction after mastectomy or to correct under- or non- developed breasts In the United States, approximately 4 million women, more than 3% of the female population, have breast implants In 2006, breast augmentation was the most commonly performed cosmetic surgery procedure in the US with an estimated 329,000 procedures. This represents an increase of over 300% in the past decade

4 Background Furthermore, the number of Canadian and American women who undergo cosmetic breast augmentation is expected to increase, given the decision of Health Canada and the US Food and Drug Administration in 2006 to reapprove silicone gel-filled breast implants for general cosmetic use There is widespread concern about the possible long-term health effects among women who have received breast implants for cosmetic purposes

5 Objectives This study, the largest cohort study undertaken to date, examined the cancer and cause-specific mortality in a cohort of 24,558 women with breast implants and 15,893 women who underwent other cosmetic procedures in Ontario and Quebec between 1974 and 1989

6 Methods – Study Population Among women, ages 18+, who were residents of ON and QC, and who received the cosmetic surgeries in , Exposed population: –Those who received bilateral cosmetic breast implants –Type of fills: silicone gel filled (SGFI), saline, saline and silicone combined –Type of envelopes: silicone and polyurethane Comparison population: –Those who received other cosmetic surgeries at the same practices –Eligible procedures: chemical peel, coronal brow lift, otoplasty, rhinoplasty, rhytidectomy, or blepharoplasty

7 Methods – Study Population Plastic surgery patients were frequency matched to the breast implant recipients by –year of entry into the cohort, and –surgeon Exclusion Criteria: –Had previous breast surgery –Received other types of silicone or artificial implants –Received substantial doses of silicone –Had a history of cancer prior to index surgery –Had a male genotype

8 Methods – Study Population After using the exclusion criteria, Exposed population: 24,558 women (7,153, ON; and 17,405, QC) Comparison population: 15,893 patients (4,418, ON; and 11,475, QC)

9 Methods – Study Population Case ascertainment: –Incidence cases of cancer were identified through record linkage of the personal identifying information of the cohort to that in Canadian Cancer Registry –The mortality experience of the cohort was ascertained through record linkage to the Canadian Mortality Database End of follow-up: December 31, 1997 The proportion of all cancers and breast cancers that were confirmed histologically was 82% and 93%, respectively

10 Methods – Statistical Analysis Cancer incidence and mortality of augmented women were compared to the general population using standardized incidence and mortality ratios (SIRs and SMRs) Comparisons between implant patients to surgical controls were performed using Poisson regression Stratified analyses were also conducted to examine cancer risks and mortality across implant and surgery characteristics of the implant population The comparisons were done for patients with one or more year of follow-up

11 Results for Cancer Incidence

12 Results The median ages at surgery were 31.3 for implant group, and 31.9 for control group. Over half of the implants were received by women between the ages of 25 and 34 More than 70% of the women in the implant and control cohorts were followed for at least 10 years The length of follow-up was longer among Quebec implant patients (15.4 years), relative to their Ontario counterparts (13.8 years) The majority of women (80%) received implants that were filled with silicone

13 Standardized Incidence Ratios (SIR) for Selected Cancers among Implant Patients

14 Standardized Incidence Ratios (SIR) for Selected Cancers among Control Cohort

15 Relative Risks (RR) of Cancer Incidence for Breast Implant vs. Control Patients

16 Relative Risks (RR) of Breast Cancer for Selected Implant Surgery Characteristics, Compared to Other Plastic Surgery Patients

17 Relative Risks (RRs) of Breast Cancer for Selected Breast Implant Characteristics

18 Relative Risks (RR) of Breast Cancer for Selected Implant Characteristics, by Site of Implantation

19 Results for Cause- specific Mortality

20 Standardized Mortality Ratios (SMRs) among Breast Implant Patients

21 Standardized Mortality Ratios (SMRs) among Plastic Surgery Patients

22 Mortality experience of Augmented Women Compared to Other Plastic Surgery Patients

23 Standardized Mortality Ratios (SMRs) for Suicides among the Cohort Relative to the General Population

24 Conclusions Comparisons to the general population indicated significantly reduced rates of cancer for all sites combined and breast cancer in both the implant and other surgery cohorts Overall cancer incidence rates were similar between the implant and other plastic surgery patients. However, augmented women had lower breast cancer rates than the plastic surgery patients Women who received breast implants had a lower mortality risk than the general population, and a risk similar to women who received other cosmetic surgeries

25 Conclusions In contrast, both the breast implant and other surgery patients had higher suicide rates No differences in mortality were found between the implant and other surgeries group for any of the 20 causes of death examined Serious consideration should be given to providing consultation for patients who are considered by the plastic surgeon to be at high risk for psychiatric disorder or suicide

26 Next Steps To evaluate risk factors for suicide among women who undergo cosmetic surgery To determine whether cosmetic implants impair the early detection of breast cancer and adversely influence survival Although the women were followed up to 24 years, given that most received implants at a relatively young age and that, in general, the risk of cancer increases with age, continued follow-up and analysis of this cohort is recommended

27 Acknowledgements We are especially grateful to the participation of the plastic surgeons in Ontario and Quebec, and for the opportunity to access provincial cancer registry data. We thank Drs. Louise Duranceau, Pierre Langlois, Walter Peters and Sylvie Bérubé, and Ms. Gemma Lee, for their support in the study design and data collection. We thank Drs Louise Brinton and Anthony Miller for their comments on an earlier draft of the incidence paper. Finally, we thank the Occupational Health and Research Division at Statistics Canada for linking the cohort to the national cancer registry and vital statistics databases.

28 Thank You