Patient-reported Quality of Life Following Treatment of Prostate Cancer With Proton Therapy

Abstract

Purpose/Objective(s): To evaluate patient-reported quality of life (QOL) after treatment with proton therapy for prostate cancer using the Expanded Prostate Index Composite questionnaire (EPIC). Materials/Methods: From 2006 to 2007, 366 men were treated for prostate cancer with proton therapy to doses of 78-82 Gy (RBE) at 2 Gy per fraction and enrolled on an outcomes-tracking protocol. Patients routinely responded to the 50-question EPIC at baseline and every 6-12 months after treatment. Patients were excluded from the analysis if they received androgen deprivation therapy or weekly docetaxel or died within 3 months of treatment, leaving 268 men for analysis, including 50% low-risk, 47% intermediate-risk, and 3% high-risk patients. The mean age at the start of treatment was 67 years old and 91% were white. Baseline patient-related medical characteristics included diabetes (14%), hypertension (51%), high cholesterol (54%), and blood thinners (50%). Results: EPIC data was available for 94%, 96%, 90%, and 78% at 6 months, 1, 2, and 3 years after completion of treatment. The baseline, 6 month, 1-, 2-, and 3year QOL subscale data are shown in the Table. For the group as a whole, urinary and bowel subscales were at their lowest (worse QOL) at 1 year and subsequently improved over the following 2 years. Sexual subscales had their sharpest decline over the first year. Univariate analysis demonstrated a significantly worse sexual bother score associated with high cholesterol (p Z 0.03) and a trend in men with diabetes (p Z 0.07). Worse sexual function score was associated with blood thinner use (p Z 0.05). No other factors were significant for any other sub scale. Responses to specific questions at baseline and 2 years included: 3% and 3% requiring 1 pad for urinary incontinence daily, 2% and 3% reporting dripping of urine being a moderate or big problem, 2% and 3% experienced rectal incontinence > weekly, 4% and 4% experienced bloody stools > half the time, 1% and 2% reported that losing control of stool was a moderate or big problem. At baseline, 64% reported erections firm enough for intercourse, 67% had sexual intercourse monthly, and 41% had sexual intercourse weekly. At 2 years, 46% reported erections firm enough for intercourse, 52% had sexual intercourse monthly, and 29% had sexual intercourse weekly. Conclusions: In the first 3 years after treatment with proton therapy, QOL data as reported by EPIC demonstrated promising results with the largest decline at 1 year after treatment. Longer follow-up is needed to confirm these findings. Author Disclosure: B.S. Hoppe: None. R.C. Nichols: None. R. Henderson: None. W.M. Mendenhall: None. C. Williams: None. J. Costa: None. C.G. Morris: None. Z. Su: None. Z. Li: None. N.P. Mendenhall: None.