This study attempted to determine whether the Gleason score (GS) assigned at a comprehensive cancer center better predicts risk of biochemical failure (BF) after prostate radiotherapy compared with the GS of the referring institution (RI). Between 1994 and 2007, 1649 men received radiotherapy for prostate cancer at Fox Chase Cancer Center (FCCC). The Cox proportional hazard regression was used for inferences about the relationship of time to BF and GS. Harrell’s C-index (HCI) was used to assess concordance in the Cox regression between predicted and observed events. The discordance rate was 26% for any change in either major or minor Gleason pattern. In the RI GS 2 through 6 group, 79 (8%) patients were upgraded to GS 7. Twenty percent of patients with RI GS 7 were downgraded and 2% were upgraded. In the RI GS 8 through 9 group, 58% were downgraded to GS 6 (12%) or GS 7 (88%). The FCCC GS altered the NCCN risk group assignment in 144 men (9%): 92 (64%) men to lower risk and 52 (36%) to higher risk. FCCC GS was a stronger predictor of BF; the hazard ratios for GS 2 through 6 (ref), 3+4, 4+3, and 8 through 9 were 1.00 (ref), 1.82, 4.14, and 2.92, respectively. In contrast, the hazard ratios for the RI GS were 1.00 (ref), 1.53, 2.44, and 1.76, respectively. FCCC GS (HCI=0.76) had improved performance compared with RI GS (HCI=0.74). Changes in GS were common and the GS assigned by a comprehensive cancer center provided better BF risk stratification and prognostication for patients. Changes in GS may impact treatment recommendations in 9% to 26% of patients.
Natasha C. Townsend, Karen Ruth, Tahseen Al-Saleem, Eric M. Horwitz, Mark Sobczak, Robert G. Uzzo, Rosalia Viterbo, and Mark K. Buyyounouski
Jeffrey M. Martin, Tianyu Li, Matthew E. Johnson, Colin T. Murphy, Alan G. Howald, Marc C. Smaldone, Alexander Kutikov, David Y.T. Chen, Rosalia Viterbo, Richard E. Greenberg, Robert G. Uzzo, and Eric M. Horwitz
Purpose: Characterize use of postprostatectomy radiation (PPRT) for patients with prostate cancer at an NCI-designated comprehensive cancer center. Methods: We queried our prospective prostate cancer database for patients treated with 60 to 68 Gy of radiation therapy (RT) to the prostate bed after prostatectomy from 2003 to 2011. Prostatectomy cases were obtained from billing records. Patients with an intact prostate treated with definitive RT served as a control for the change in volume of patients with prostate cancer treated in the department. Chi-square analysis assessed differences between adjuvant and salvage RT cohorts. Spearman correlation assessed yearly trends in prostate-specific antigen (PSA) level at the time of referral for RT. Linear regression models tested trends for number of PPRT cases, prostatectomies, and patients with intact prostate receiving radiation across years. Results: PPRT was used to treat 475 men at Fox Chase Cancer Center from 2003 to 2011 (83 adjuvant and 392 salvage). Over time, an increased proportion of patients receiving RT to the prostate were treated with PPRT. No increase was seen in the proportion of patients treated with adjuvant RT compared with salvage RT (P=.5). Patients receiving adjuvant RT were younger, had higher pathologic Gleason score, pathologic T stage, and rates of positive margins than those receiving salvage RT. Pre-RT PSA values were inversely correlated with year (P=.005). The number of patients referred for salvage RT with a PSA of 0.5 ng/mL or less increased significantly from 7.9% in 2003 to 26.6% in 2011 (P=.002). Conclusions: A larger proportion of patients treated with RT for localized prostate cancer are now receiving PPRT. No increase was seen in the proportion of patients treated with adjuvant RT. Over time, patients with lower PSAs were referred for salvage RT.