Bilateral oophorectomy and breast cancer risk reduction among women with a family history.

PURPOSE

We investigated whether removal of the ovaries is an appropriate risk reduction option for women at elevated risk of breast cancer based on family history of breast cancer.

PATIENTS AND METHODS

This question was investigated among a group of 851 women less than age 60 who underwent bilateral oophorectomy between 1970 and 1994 for various reasons. Questionnaire information was collected from 680 (80%) and women were grouped into family risk categories. Reported occurrences of breast cancer were compared to expected rates based on the Gail model.

RESULTS

The number of observed breast cancers among women in the cohort was lower than expected for all levels of familial risk, with women in the highest risk groups experiencing about half to one-fourth the number of cancers expected. The apparent protective effect of oophorectomy was stronger among women who were both premenopausal and less than age 50 at time of surgery.

CONCLUSION

These data support oophorectomy as a valid breast cancer prevention option for women of all risk levels.