Search

51 Background: RP, EBRT, and PI for the treatment of clinically localized prostate cancer may negatively impact sexual function. Predictions of treatment-related sexual problems from patient-reported, prospective data may be useful in decision-making. Methods: Patient-reported data on treatment-related sexual problems was obtained from 4 prospective, longitudinal, health-related quality-of-life (HRQOL) protocols comprising 2,668 patients treated between 1999 and 2011 by RP (n = 1,294), EBRT (n = 630), and PI (n = 744). A single HRQOL instrument was not uniformly used for each study, although questions pertaining to the quality and frequency of erections were identical among the studies. Only those patients with quality of erections sufficient for intercourse were included in the model. The endpoint of the model was erections suitable for intercourse on at least half of attempts at 2 years after treatment, with or without the use of oral medications. Cox proportional hazards regression analysis was used to model the clinical information and follow-up data. Internal validation was performed using bootstrapping. Results: Overall, 931 (74%), 249 (42%), and 323 (45%) patients treated by RP, EBRT, and PI were considered to be potent at baseline. Significant differences in baseline characteristics such as patient age, ethnicity, and disease severity existed between the treatment groups. The potency rate at 2 years for 1,215 patients who were potent at baseline and had complete follow-up data was 38%, 51%, and 61% for patients treated by RP, EBRT, and PI, respectively (p < 0.001). In multivariable analysis, age (p < 0.001), baseline frequency of erections (p < 0.001), EBRT (p < 0.001), PI (p < 0.001), PSA (p = 0.001), and institution (p = 0.006), were associated with potency. A nomogram based on the predictive parameters had a concordance index of 0.72 and predictions were well-calibrated with observed outcome. Conclusions: An externally-validated nomogram that predicts 2-year potency after treatment for localized prostate cancer has been developed and may be useful for patient counseling regarding treatment options.

55 Background: RP, EBRT, and PI for treatment of clinically localized prostate cancer may negatively impact bowel function. Predictions of treatment-related bowel problems from patient-reported, prospective data may be useful in treatment decision-making. Methods: Patient-reported data on treatment-related bowel problems was obtained from 4 prospective, longitudinal, health-related quality-of-life (HRQOL) protocols comprising 2,668 patients treated between 1999 and 2011 by RP (n=1294), EBRT (n=630), and PI (n=744). A single HRQOL instrument was not uniformly used for each study, though all patients were asked if they experienced bother related to bowel problems using a similar 5-point scale. Patient responses were obtained at baseline and at 2 years after treatment. The endpoint of the model was bowel dysfunction, defined as bowel symptoms that were identified as a moderate-to-big problem. Cox proportional hazards regression analysis was used to model the clinical information and follow-up data. Internal validation was performed using bootstrapping. Results: Significant differences in baseline characteristics such as patient age, ethnicity, and disease severity existed between the treatment groups. Overall, 46 patients (2%) with complete data available had bowel dysfunction at baseline, including 11 (1%), 19 (4%), and 16 (3%) patients treated by RP, EBRT, and PI, respectively (p = 0.001). The overall rate of bowel dysfunction at 2 years in those patients with no bowel dysfunction at baseline was 2%, 10%, and 4% for patients treated by RP, EBRT, and PI, respectively (p < 0.001). In multivariable analysis, EBRT (p < 0.001), PI (p < 0.001), baseline bowel symptoms (p < 0.001), and institution (p = 0.04) were associated with bowel dysfunction. A nomogram based on the predictive parameters had a concordance index of 0.73 and predictions were well-calibrated with observed outcome. Conclusions: An externally validated nomogram that predicts 2-year incidence of bowel dysfunction after treatment for localized prostate cancer has been developed and may be useful for patient counseling regarding treatment options.