PT - JOURNAL ARTICLE AU - Porter, Geoff AU - Wagar, Brandon AU - Bryant, Heather AU - Hewitt, Maria AU - Wai, Elaine AU - Dabbs, Kelly AU - McFarlane, Anne AU - Rahal, Rami TI - Rates of breast cancer surgery in Canada from 2007/08 to 2009/10: retrospective cohort study AID - 10.9778/cmajo.20130025 DP - 2014 Apr 01 TA - CMAJ Open PG - E102--E108 VI - 2 IP - 2 4099 - http://www.cmajopen.ca/content/2/2/E102.short 4100 - http://www.cmajopen.ca/content/2/2/E102.full AB - Background Surgery is a common and important component of breast cancer treatment. We assessed the rates of breast cancer surgery across Canada from 2007/08 to 2009/10. Methods We used hospital and day surgery data from the Canadian Institute for Health Information to assemble a cohort of women who had undergone breast cancer surgery. We identified the index surgical procedure and subsequent surgical procedures performed within 1 year for each woman included in the analysis. We calculated the crude mastectomy rate for each province, and we calculated the adjusted mastectomy rate for select jurisdictions using a logistic regression model fitted using age, neighbourhood income quintile and travel time. Results In total, 57 840 women underwent breast cancer surgery during the study period. Among women with unilateral invasive breast cancer, the crude mastectomy rate was 39%. Adjusted rates for mastectomy varied widely by province (26%–69%). The rate of re-excision within 1 year for women who had breast-conserving surgery as their index procedure was 23% and varied by province in terms of frequency and type (mastectomy or repeat breast-conserving surgery). Among women who underwent mastectomy for unilateral invasive breast cancer, 6% also underwent contralateral prophylactic mastectomy, and 7% had immediate breast reconstruction following surgery. Of mastectomy procedures, 20% were performed as day surgery; for breast-conserving surgery, 70% were performed as day surgery. Interpretation There is substantial interprovincial variation in surgical care for breast cancer in Canada. Further research is needed to better understand such variation, and continued monitoring should be the focus of quality initiatives.