Association between depressive disorders and risk of breast cancer recurrence after curative surgery

The aim of the study was to investigate the association between depressive disorders and risk of tumor recurrence in patients with breast cancer after curative surgery. A nationwide cohort study between January 2001 and December 2007 was conducted. Data were taken from the Taiwan National Health Insurance Research Database. Among 30,659 newly diagnosed breast cancer patients, we identified 1147 breast cancer patients with depressive disorders and 2294 matched breast cancer patients without depressive disorders, both of whom received curative breast surgery between January 2003 and December 2007. The risk of first tumor recurrence was compared between patients who developed depressive disorders after breast surgery (depressive disorder cohort, n=1147) and matched patients who did not develop depressive disorders (matched nondepressive disorder cohort, n=2294). Cumulative incidences and hazard ratios (HRs) were calculated after adjusting for competing mortality. The depressive disorder cohort had a higher rate of recurrence when compared with the matched nondepressive disorder cohort (17.1% vs 12.5%; P<.001). The Kaplan-Meier analysis revealed a predisposition of patients with depressive disorders to suffer from recurrence (log-rank test, P<.001). After multivariate adjustment, the HR for subsequent recurrence among the depressive disorder cohort was 1.373 (95% confidence interval 1.098-1.716, P=0.005). Moreover, the depressive disorder cohort had higher risk of overall mortality even though not significant after adjusted (adjusted HR 1.271, 95% confidence interval 0.930-1.737, P=0.132). Depressive disorder was associated with a higher risk of breast cancer recurrence among patients after curative breast surgery.