PURPOSE - To retrospectively evaluate the role of adjuvant radiotherapy (ART) as monotherapy in a cohort of prostate cancer patients with undetectable prostate-specific antigen (PSA) after surgery and to propose a risk stratification system.
METHODS - Between 2003 and 2010, 174 consecutive patients were treated with ART (median dose 71 Gy) at a single institution. Subsequently, we assigned a score of 1 to the following risk factors (RF): T stage ≥3b, presurgical PSA ≥10 ng/mL, pathologic Gleason score (GS) ≥4 + 3, and positive surgical margin (R1). The scores were then summed to stratify the population into low risk (LR), intermediate risk (IR), and high risk (HR).
RESULTS - Median follow-up was 61 months (range 4-105). Five-year biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and overall survival (OS) were respectively 93%, 97.1%, and 98.6%. On univariate analyses, GS was the only variable related to bRFS (p = 0.04) and to cRFS (p = 0.05). Any variable was related to OS. Kaplan-Meier analysis showed that HR patients (3-4 RF) had a worse bRFS (p = 0.02) compared to LR patients (0 RF or R1 as single RF); IR patients (1-2 RF) had a lower bRFS compared to LR patients (p = 0.06). Patients with R1 as single RF have the same bRFS as patients with 0 RF (p = 0.6) and are considered as LR patients.
CONCLUSIONS - Adjuvant radiotherapy leads to excellent bRFS and cRFS rates at 5 years (93.3% and 97.1%, respectively) in our population. Patients with multiple RF are at higher risk of bRFS. Patients with R1 as single RF have bRFS rates comparable to patients without any RF.
Tumori. 2016 Mar 22 [Epub ahead of print]
Mario Levis, Alessia Guarneri, Niccolò Giaj Levra, Daniel E Spratt, Sara Bartoncini, Fernando Munoz, Elisabetta Trino, Angela Botticella, Francesca Arcadipane, Umberto Ricardi
Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Radiation Oncology, AOU City of the Health and of the Science, Turin, Turin - Italy., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY - USA., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Radiation Oncology, AOU City of the Health and of the Science, Turin, Turin - Italy., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy., Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy.