Does Race Influence Health-related Quality of Life and Toxicity Following Proton Therapy for Prostate Cancer?

OBJECTIVE: This matched-paired analysis explores disparities in health-related quality of life (QOL) and common toxicities between African American (AA) and white patients following proton therapy for prostate cancer at our institution. MATERIALS AND METHODS: A total of 1536 men with clinically localized prostate cancer were treated from 2006 to 2009 with definitive proton therapy to a median dose of 78 Gy +/− androgen deprivation therapy. A cohort of 92 consecutively treated AA men was matched to a cohort of 92 white men on the basis of National Comprehensive Cancer Network risk category and age. The 2 groups were compared with regard to comorbidities, demographics, and treatment regimen. Differences in genitourinary and gastrointestinal (GI) toxicity according to the Common Terminology Criteria for Adverse Events scale and QOL data from the Expanded Prostate Index Composite 26-question questionnaire were reported. RESULTS: Median follow-up was 2.1 years. Baseline patient and treatment characteristics were similar between the 2 groups with the exception of prostate-specific antigen ≥10 (32% for AAs vs. 20% for whites; P=0.068) and use of androgen deprivation therapy (26% for AAs vs. 21% for whites; P=0.38). No difference in Expanded Prostate Index Composite 26-question sexual summary, urinary incontinence, urinary obstruction, or bowel summary scores was detected between the 2 groups, nor was there a difference in grade 2 or higher GI toxicity (P=0.45). AAs had a statistically nonsignificant higher absolute incidence of late grade 3 genitourinary toxicity (4.4% vs. 0%; P=0.12). CONCLUSIONS: After 2 years, there were no disparities in health-related QOL, physician-reported Common Terminology Criteria for Adverse Events GI toxicity, or biochemical relapse. Longer follow-up is needed to confirm these findings.