Variation in rates of uptake of preventive options by Canadian women carrying the BRCA1 or BRCA2 genetic mutation.

BACKGROUND

Women with a BRCA1 or BRCA2 genetic mutation have several options for cancer prevention, including prophylactic surgery, chemoprevention and screening. In this study we report on preventive practices used by women with and without breast cancer and examine differences in their selection of preventive practices according to geographic area in Canada.

METHODS

Canadian women with a BRCA1 or BRCA2 mutation were followed after genetic testing and questioned about their preventive practices. Women reported on uptake of prophylactic mastectomy, prophylactic oophorectomy, tamoxifen or raloxifene usage and screening practices. We analyzed the uptake of each preventive option and completed a subanalysis according to the geographic area in Canada where genetic testing was provided.

RESULTS

The study included 672 women. Follow-up questionnaires were completed after a mean of 4.0 years (range 1.6-9.1 years). Of the 342 women without breast cancer, 72 (21%) had had a prophylactic bilateral mastectomy. Three hundred and sixty-three women (54%) had had a bilateral prophylactic oophorectomy. Seventeen (6%) of the 270 women without breast cancer who had not had a prophylactic mastectomy took tamoxifen, and 12 (4%) reported taking raloxifene. Of the 342 women without breast cancer, 157 (46%) had not undertaken any cancer prevention option (mastectomy, oophorectomy or treatment with tamoxifen or raloxifene). Sixty-five (39%) of the 167 women from Ontario, 19 (34%) of the 56 women from Western Canada and 73 (62%) of the 119 women from Quebec had not undertaken any preventive procedure.

CONCLUSION

Significant differences in the uptake of preventive options by women with a BRCA1 or BRCA2 mutation were observed across 3 regions of Canada. Future research is needed to explain why these differences exist.