The association of long-term treatment-related side effects with cancer-specific and general quality of life among prostate cancer survivors

Objective To examine the association between treatment-related side effects and cancer-specific and general quality of life (QOL) among long-term prostate cancer survivors. Materials and Methods Within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, we conducted telephone interviews with prostate cancer survivors (N = 518) who were 5-10 years after diagnosis. We assessed demographic and clinical information, sexual, urinary, and bowel treatment-related side effects (Expanded Prostate Cancer Index Composite), cancer-specific QOL (Functional Assessment of Cancer Therapy - total score), and general QOL (the Medical Outcomes Study Short Form 12's physical and mental subscales). Results Participants were aged 74.6 years on average, primarily White (88.4%), and married (81.7%). Pearson correlation coefficients between the 3 treatment-related side effect domains (urinary, sexual, and bowel) and QOL ranged between 0.14 and 0.42 (P <.0001). Multivariable linear regression analyses revealed that poorer urinary and sexual functioning and greater bowel side effects were independently associated with poorer cancer-specific QOL (P <.0001). Bowel and urinary functions were also associated with poorer general QOL on the Medical Outcomes Study Short Form 12's physical component summary and mental component summary (P <.05). Bowel side effects demonstrated the strongest association with all QOL outcomes. Conclusion Treatment-related side effects persisted for up to 10 years after diagnosis and continued to be associated with men's QOL. These results suggest that each of the treatment-related side effects was independently associated with cancer-specific QOL. Compared with the other Expanded Prostate Cancer Index Composite domains, bowel side effects had the strongest association with cancer-specific and general QOL. These associations emphasize the tremendous impact that bowel side effects continue to have for men many years after their initial diagnosis.