Purpose: Research on prostate cancer and quality of life (QOL) has focused on the effects of treatment type on subsequent QOL, without considering effects of depressive symptoms. The present purpose is to test the independent contribution of depressive symptoms (measured within 4 weeks after treatment) and treatment type in predicting QOL measured 4, 7, and 12 months following treatment for clinically localized prostate cancer.
Methods: The 105 patients (all Stage I-II) were newly treated with radical prostatectomy, external beam radiation (EBR) or brachytherapy. Age ranged from 42 to 80 (mean = 64); 88% Caucasian and 9% African American. Repeated measures mixed linear models were adjusted for age, race, education, and marital status.
Results: Depressive symptoms significantly (p < 0.01) predicted 8 of 10 disease-specific and 7 of 7 generic QOL outcomes. Treatment type significantly (p < 0.01) predicted urinary function and bowel bother but no generic QOL outcomes.
Conclusions: Depressive symptoms appears to predict a wider range of QOL outcomes (measured 4-12 months after treatment) than treatment type; however, when treatment is significant its effect sizes are slightly larger than depressive symptoms. Health care providers should (1) assess depressive symptoms in prostate cancer patients before and after treatment, and (2) provide psychosocial (e.g., counseling, support groups) and pharmacologic treatment options for improving depressive symptoms.