Survival Outcomes of Whole-Pelvic Versus Prostate-Only Radiotherapy for High-Risk Prostate Cancer Patients Using the National Cancer Data Base
Menée à partir de données portant sur 14 817 patients traités entre 2004 et 2006 pour un cancer de la prostate à haut risque de récidive et sans envahissement ganglionnaire détecté (durée médiane de suivi : 81 mois), cette étude évalue, du point de vue de la survie, l'intérêt d'ajouter une radiothérapie de l'ensemble de la région pelvienne à une radiothérapie de la prostate
Purpose/Objective(s) : The addition of whole-pelvic (WP) compared to prostate-only (PO) radiotherapy (RT) for clinically node-negative prostate cancer remains controversial. The purpose of our study was to evaluate the survival benefit of adding WPRT versus PO-RT for high-risk, node-negative prostate cancer, using the National Cancer Data Base (NCDB). Methods and Materials : Patients with high-risk prostate cancer treated from 2004-2006, with available data for RT volume, coded as prostate and pelvis (WPRT) or prostate alone (PO-RT) were included. Multivariate (MVA) and propensity score-matched (PSM) analyses were performed. Recursive partitioning analysis (RPA) based on OS using Gleason score (GS), T-stage, and pretreatment prostate-specific antigen (PSA) was also conducted. Results : A total of 14,817 patients were included: 7,606 (51.3%) received WPRT, 7,211 (48.7%) received PO-RT. Median follow up was 81 months (2-122). Under MVA, the addition of WPRT for high-risk patients had no OS benefit compared to PO-RT (HR, 1.05; p=0.100). On subset analysis, patients receiving dose-escalated RT also did not benefit from WPRT (HR, 1.01; p=0.908). PSM confirmed no survival benefit with the addition of WPRT for high-risk patients (HR, 1.05, p=0.141). In addition, RPA was unable to demonstrate a survival benefit of WPRT for any subset. Other prognostic factors for inferior OS under MVA included older age (HR, 1.25; p<0.001), increasing comorbidity scores (HR, 1.46; p<0.001), higher T-stage (HR, 1.17; p<0.001), PSA (HR, 1.81; p<0.001), and GS (HR, 1.29; p<0.001), and decreasing median county household income (HR, 1.15; p=0.011). Factors improving OS included the addition of androgen deprivation therapy (ADT) (HR, 0.92; p=0.033), combination external beam RT plus brachytherapy boost (HR, 0.71; p<0.001), and treatment at an academic/research institution (HR, 0.84; p=0.002). Conclusion : In the largest reported analysis of WPRT for patients with high-risk prostate cancer treated in the dose-escalated era, the addition of WPRT demonstrated no survival advantage compared to PO-RT.