Temporal trends of subsequent breast cancer among women with ovarian cancer: a population-based study

Purpose To examine trends, characteristics and outcomes of women who develop both ovarian and breast cancers. Methods This is a retrospective study examining the Surveillance, Epidemiology, and End Results Program from 1973 to 2013. Among ovarian cancer (n = 133,149) and breast cancer (n = 1,143,219) cohorts, women with both diagnoses were identified and temporal trends, tumor characteristics and survival were examined. Results There were 6446 women with both malignancies, representing 4.8% of the ovarian cancer cohort and 0.6% of the breast cancer cohort. Women with ovarian cancer who had secondary breast cancer were younger than those without secondary breast cancer early in the study period (52.3 versus 59.2 in 1973) but older in more recent years (68.5 versus 62.1 in 2013, P < 0.001). The number of breast cancer survivors who developed postcedent ovarian cancer decreased from 1.5 to 0.2% from 1979 to 2008 (relative risk reduction 90.0%, P < 0.05). Similarly, the number of ovarian cancer survivors who developed postcedent breast cancer decreased from 7.2 to 2.0% from 1973 to 2008 (relative risk reduction 72.4%, P < 0.05). Tumor characteristics were more likely to be favorable in women with ovarian cancer who developed postcedent breast cancer but unfavorable in those who had antecedent breast cancer (all, P < 0.05). Women with ovarian cancer who had secondary breast cancer had superior cause-specific survival compared to those who did not develop breast cancer regardless of breast cancer timing (P < 0.05). Conclusion Our study demonstrated that the demographics of women who develop breast cancer and ovarian cancer have changed over time and diagnosis of secondary breast cancer after ovarian cancer has decreased.