The Finnish Randomized Trial of Adjuvant Radiotherapy Versus Observation After Prostatectomy: Almost a Trial of Adjuvant Versus Late Salvage Radiotherapy

Biochemical control after adjuvant radiation therapy for prostate cancer: a unicentric, retrospective analysis

PURPOSE

To retrospectively evaluate the biochemical no evidence of disease (bNED) and late side effects after adjuvant radiotherapy in prostate cancer patients.

METHODS

Patients (n = 85) treated with external beam radiotherapy between 1997 and 2013 following radical prostatectomy (RPE) with pathological tumour stage pT2c with positive surgical margins or pT3 and pT4 tumours with or without positive margins who presented with a postoperative and a preradiation prostate-specific antigen (PSA) level below 0.1 ng/ml. The mean dose applied was 66 Gy with conventional fractionation (4 field box-technique). No androgen deprivation therapy was administered, and patients with incomplete data (missing Gleason score, pT stage, or PSA values postoperatively and/or prior to radiation at the presentation at our department) have been excluded from the analysis. Biochemical recurrence was defined as reaching a PSA level > 0.2 ng/ml during follow-up and bNED rates were assessed. In addition, patients were divided into two groups according to the Roach formula for predicting the risk of pelvic node involvement at a cut-off value of 15%. Late urogenital and gastrointestinal side effects (EORTC/RTOG) were assessed.

RESULTS

After a median follow-up of 60 months the bNED rate was 88% at 5 years and 72% at 10 years for all patients. Patients with low risk of lymph node involvement (group < 15%) had a 5 year and 10 year bNED of 97% and 85%, while patients with high risk of positive lymph node involvement (group > 15%) showed corresponding bNED rates of 77% and 52%, respectively. A significant difference according to the Roach stratification was detected (p ≤ 0.002). Late urogenital (UG) and gastrointestinal (GI) grade ≥ 2 side effects were detected in 10% and 15%, respectively.

CONCLUSION

Postoperative radiotherapy with an average dose of 66 Gy to the prostatic fossa following RPE provides excellent tumour control rates with acceptable side effects. Patients with a higher risk of positive lymph nodes (> 15%) according to the Roach formula show significant worse tumour control rates.

Systematic review and meta-analysis of trials evaluating the role of adjuvant radiation after radical prostatectomy for prostate cancer: Implications for early salvage

INTRODUCTION

Recent reports suggest that early salvage radiation (esRT) is non-inferior to adjuvant radiation (aRT) for adverse pathological features at radical prostatectomy. However, aRT was accepted as a standard treatment primarily based on effects on biochemical progression-free survival (bPFS). In order to understand the merits of esRT, the objective was to reassess if aRT vs. observation is associated with improved overall survival (OS).

METHODS

A systematic review and meta-analysis of published randomized trials evaluating aRT was performed. The primary outcome was OS. Secondary outcomes were metastasis-free survival (MFS), loco-regional recurrence-free survival (RFS), bPFS, and adverse events. We performed a random-effects meta-analysis.

RESULTS

Four randomized trials including 2068 patients with a median followup of 8.7-12.6 years were identified. While all trials reported a bPFS benefit, only one reported an OS benefit. Upon meta-analysis, no significant OS benefit was detected with aRT vs. observation (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.61-1.33), although consistent bPFS (HR 0.47, 95% CI 0.41-0.54) and local-RFS (HR 0.54, 95% CI 0.39-0.73) benefits were noted. There is an uncertain MFS benefit with aRT (HR 0.79, 95% CI 0.62-1.01), and the effect is largely driven by one trial with a notable risk of bias. There was also a risk of overtreatment, with 35-60% of patients being biochemical recurrence-free with observation alone. Adverse events risk was greater with aRT vs. observation.

CONCLUSIONS

Although aRT vs. observation provides a bPFS benefit related to local control, there is no clear OS or MFS benefit, a greater risk of adverse events, and a risk of overtreatment. By extension, these data have implications for patient selection and counselling for esRT.