Assessing ovarian cancer risk when considering elective oophorectomy at the time of hysterectomy.

Objective: To develop a risk-factor score that may provide additional guidance to women and their physicians regarding elective bilateral salpingo-oophorectomy at the time of hysterectomy.

Methods: From a case-control study conducted from 1992 to 2008 in women residing in eastern Massachusetts or New Hampshire, we selected 1,098 women with invasive ovarian cancer (case group) and 1,363 for the control group who were older than 40 years and had neither hysterectomy nor a personal or family history of breast or ovarian cancer. Using logistic regression, we identified key risk factors and built a risk score. The score was separately assessed in 126 women in the case group and 156 in the control group with excluded prior hysterectomy to determine whether women who developed ovarian cancer could have been distinguished.

Results: Summing eight conditions found to be associated with ovarian cancer (Jewish ethnicity, less than 1 year of oral contraceptive use, nulliparity, no breastfeeding, no tubal ligation, painful periods or endometriosis, polycystic ovary syndrome or obesity, talc use), we created a five-level score. Assigning average risk to those with a score of 2, the odds ratios varied from 0.56 (95% confidence interval [CI] 0.42-0.74) for a score of 0-1 to 3.30 (95% CI 2.50-4.35) for a score of 5 or greater (P trend <.001). The risk score was higher for women who developed ovarian cancer after hysterectomy than those who did not (P=.01). Lifetime risks for ovarian cancer for a woman at age 40 years are changed from 1.2% with a 0-1 score to 6.6% with a score of 5 or higher.

Conclusion: We developed a risk-assessment tool that can quantify women's risk for ovarian cancer and should be validated in other data sets.