Effect of depression on diagnosis, treatment, and survival of older women with breast cancer.

OBJECTIVES: To assess the effect of a prior diagnosis of depression on the diagnosis, treatment, and survival of older women with breast cancer.
DESIGN: Retrospective analysis of records from Surveillance, Epidemiology and End Results (SEER) and Medicare claims.
SETTING: Registries from seven major cities and five states. PARTICIPANTS: A total of 24,696 women aged 67 to 90 diagnosed with breast cancer between 1993 and 1996 and included in the SEER Medicare linked database were studied. MEASUREMENTS: Information on patient demographics, tumor characteristics, treatment received, and survival were obtained from SEER, and the Medicare inpatient and professional charges for the 2 years before diagnosis were searched for a diagnosis of depression.
RESULTS: A total of 1,841 of the 24,696 women (7.5%) had been given a diagnosis of depression sometime in the 2 years before the diagnosis of breast cancer. There was no difference in tumor size or stage at diagnosis between depressed and nondepressed women. Women diagnosed with depression were less likely to receive treatment generally considered definitive (59.7% vs 66.2%, P<.0001), and this difference remained after controlling for age, ethnicity, comorbidity, and SEER site. Also, women with a prior diagnosis of depression had a higher risk of death (hazard ratio=1.42; 95% confidence interval= 1.13-1.79) after controlling for other factors that might affect survival. The higher risk of death associated with a prior diagnosis of depression was also seen in analyses restricted to women who received definitive treatment.
CONCLUSION: Women with a recent diagnosis of depression are at greater risk for receiving nondefinitive treatment and experience worse survival after a diagnosis of breast cancer, but differences in treatment do not explain the worse survival.