Published online Jul 24, 2022. doi: 10.5306/wjco.v13.i7.652
Peer-review started: March 27, 2022
First decision: May 12, 2022
Revised: June 4, 2022
Accepted: July 5, 2022
Article in press: July 5, 2022
Published online: July 24, 2022
Processing time: 116 Days and 16.2 Hours
Approximately 30% of patients with localized prostate cancer (PCa) who undergo radical prostatectomy will develop biochemical recurrence. In these patients, the only potentially curative treatment is postoperative radiotherapy (PORT) with or without hormone therapy. However, the optimal radiotherapy dose is unknown due to the limited data available.
Our article analyses the changing landscape of the management of prostate cancer patients who receive postoperative radiotherapy, shedding light on an area, optimal radiation dose, applicable to clinical practice, for which the current evidence base is constantly fluctuating with a growing need to optimize the treatment of these patients.
To determine whether the postoperative radiotherapy dose influences biochemical failure-free survival (BFFS) in patients with prostate cancer.
Retrospective analysis of patients who underwent radical prostatectomy for PCa followed by PORT-either adjuvant radiotherapy or salvage radiotherapy-between April 2002 and July 2015. From 2002 to 2010, the prescribed radiation dose to the surgical bed was 66-70 Gy in fractions of 2 Gy; from 2010 until the present, the prescribed dose was 70-72 Gy. Patients were grouped into three categories according to the total dose administered: 66-68 Gy, 70 Gy, and 72 Gy. The primary endpoint was BFFS, defined as the post-radiotherapy prostate-specific antigen (PSA) nadir + 0.2 ng/mL. Secondary endpoints were overall survival (OS), cancer-specific survival (CSS), and metastasis-free survival (MFS; based on conventional imaging tests). Treatment-related genitourinary (GU) and gastrointestinal (GI) toxicity was evaluated according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Finally, we aimed to identify potential prognostic factors. BFFS, OS, CSS, and MFS were calculated with the Kaplan-Meier method and the log-rank test. Univariate and multivariate Cox regression models were performed to explore between-group differences in survival outcome measures.
301 consecutive patients were included. At a median follow-up of 113 mo (range, 4-233), 5-and 10-year BFFS rates were 78.8% and 73.7%, respectively, with OS rates of 93.3% and 81.4%. The 5-year BFFS rates in the three groups were as follows: 69.6% (66-68Gy), 80.5% (70Gy) and 82.6% (72Gy) (P = 0.12): at 10 years, the corresponding rates were 63.9%, 72.9% and 82.6% (P = 0.12), respectively. No significant between-group differences were observed in MFS, CSS, or OS. No significant differences were found in GU or GI toxicity between the 3 radiation-dose groups except acute grade 1 GI toxicity that was observed in 16 (29.6%), 23 (26.7%) and 2 (5.6%) patients in each group (66-68Gy, 70Gy and 72Gy), respectively (P = 0.011).
Postoperative radiotherapy dose intensification in PCa is not superior to conventional radiotherapy treatment.
A more comprehensive analysis of the radiation dose in prostate cancer patients who receive postoperative radiotherapy could help to better elucidate the true potential of dose intensification, thus allowing for more individualized treatment.