RESUMEN
PURPOSE: Conventional prostate cancer risk stratification results in considerable heterogeneity within each prognostic group. Men with pathologic grade Group 4 (Gleason score 8) but otherwise low-risk features have been identified as a favorable subset of high-risk prostate cancer. Given recent randomized data supporting improved cancer outcome with brachytherapy in intermediate- and high-risk prostate cancer, we sought to evaluate brachytherapy utilization and overall survival (OS) for these patients. METHODS AND MATERIALS: We queried the National Cancer Database for clinical T1c-T2a N0 M0 prostate cancer with prostate-specific antigen <10 ng/mL and Gleason score 8 adenocarcinoma on biopsy. All patients received androgen deprivation therapy and either external beam radiation therapy (EBRT) alone, brachytherapy alone, or a combination of EBRT with brachytherapy boost (brachytherapy + EBRT). Kaplan-Meier OS estimates as well as univariate and multivariate Cox proportional hazards regression analyses were performed. Propensity score-matched analyses were performed to further control for baseline confounders. RESULTS: Four thousand four hundred ninety-six patients were identified with a median followup of 62.5 months (range, 2.3-119.8). Median age was 72 years (range, 41-90+). Utilization of brachytherapy decreased from 2004 to 2009. The odds ratio for brachytherapy by year (continuous variable) was 0.86 (p < 0.001). Five-year OS was 84%, 88%, and 89% for the EBRT alone, brachytherapy alone, and brachytherapy + EBRT groups, respectively. On multivariate analysis, higher median income, low comorbidity score, and treatment with brachytherapy alone (hazard ratio, 0.66; p = 0.005) or brachytherapy + EBRT (hazard ratio, 0.70; p = 0.001) remained associated with longer OS. Propensity score matching confirmed longer OS associated with either brachytherapy regimen. CONCLUSIONS: Of those men with World Health Organization pathologic grade Group 4 (Gleason score 8) prostate cancer and otherwise favorable prognostic features treated with androgen deprivation therapy and radiation therapy, longer OS was achieved when prostate brachytherapy was included, whether used alone or in combination with supplemental EBRT. In spite of these excellent outcomes, prostate brachytherapy utilization is declining in the United States.
RESUMEN
PURPOSE: To evaluate usage trends and identify factors associated with proton beam therapy (PBT) compared to alternative forms of external beam radiation therapy (RT) (EBRT) for localized prostate cancer. PATIENTS AND METHODS: The National Cancer Database was queried for men with localized (N0, M0) prostate cancer diagnosed between 2004 and 2013, treated with EBRT, with available data on EBRT modality (photon vs. PBT). Binary multiple logistic regression identified variables associated with EBRT modality. RESULTS: In total, 143,702 patients were evaluated with relatively few men receiving PBT (5,709 [4.0%]). Significant differences in patient and clinical characteristics were identified between those men treated with PBT compared to those treated with photon (odds ratio [OR]; 95% CI). Patients treated with PBT were generally younger (OR = 0.73; CI: 0.67-0.82), National Comprehensive Cancer Network low-risk compared to intermediate (0.71; 0.65-0.78) or high (0.44; 0.38-0.5) risk, white vs. black race (0.66; 0.58-0.77), with less comorbidity (Charlson-Deyo 0 vs. 2+; 0.70; 0.50-0.98), live in higher income counties (1.55; 1.36-1.78), and live in metropolitan areas compared to urban (0.21; 0.18-0.23) or rural (0.14; 0.10-0.19) areas. Most patients treated with PBT travelled more than 100 miles to the treatment facility. Annual PBT utilization significantly increased in both total number and percentage of EBRT over time (2.7%-5.6%; P<0.001). PBT utilization increased mostly in men classified as National Comprehensive Cancer Network low-risk (4%-10.2%). CONCLUSION: PBT for men with localized prostate cancer significantly increased in the United States from 2004 to 2013. Significant demographic and prognostic differences between those men treated with photons and protons were identified.