Association between baseline physical function and comorbidity status with patient-reported quality of life after prostate cancer treatments: Combined analysis of two prospective cohort studies.

Abstract

6107 Background: Treatment-related bowel, urinary, and sexual dysfunction in prostate cancer patients varies by treatment type, baseline function and other patient factors. To better predict patient outcomes after treatment, we examined the impact of comorbidity on these quality of life (QOL) outcomes in a secondary data analysis of two pooled, prospective cohort studies. Methods: A total of 697 patients from 3 academic hospitals who received radical prostatectomy, external beam radiation, or brachytherapy were included. Using a validated instrument, patients reported bowel, urinary, and sexual symptoms pretreatment, and at 3, 12, 24, and 36 months after treatment. Baseline physical function was measured by the physical component summary score (PCS) of the SF-12 using patient report. Comorbidity as measured by the Index of Co-Existent Disease (ICED) was obtained from medical record review. Repeated QOL measurements were analyzed using a mixed modeling method, by random coefficient modeling. Separate models were built for each outcome using bowel, urinary, and sexual scale scores at each time point.Covariates in all models included baseline age, education, ICED, and PCS. Results: Approximately 70% of patients had one or more comorbid conditions at baseline. After adjusting for age and education in mixed-models, we found baseline comorbidity was independently associated with more sexual dysfunction (p<.001) and urinary incontinence (p=.03). Worse baseline physical functioning was independently associated with more bowel problems (p<.001) and sexual dysfunction (p<.001). There were no treatment by comorbidity or physical functioning interactions. Conclusions: Comorbidity and worse physical functioning at baseline are significantly associated with poorer bowel, urinary, and sexual function after treatment for prostate cancer, but the associations do not appear to differ by treatment. Patients with comorbidity recovered more slowly. This information may help patients and their physicians anticipate outcomes after surgical and radiation treatments.