Adjuvant versus salvage radiotherapy in prostate cancer: multi-institutional retrospective analysis of the Spanish RECAP database

Purpose

To compare adjuvant radiotherapy (ART) to salvage radiotherapy (SRT) after radical prostatectomy (RP) in a cohort of prostate cancer (PCa) patients. The primary aim was to comparatively assess 2- and 5-year biochemical relapse-free survival (BRFS). A secondary aim was to identify predictors of survival.

Patients and methods

Data were acquired from the RECAP database, a population-based prostate cancer registry in Spain. Inclusion criteria included RP (with or without lymphadenectomy) followed by ART or SRT. A total of 702 patients were analyzed. Pre-RT PSA values (>0.5 vs. ≤0.5 ng/ml), pathological stage (T1–2 vs. T3–4), post-surgical Gleason score (≤7 vs. 8–10), margin status (positive vs. negative), hormonal treatment (yes vs. no), and RT dose (≤66 Gy vs. >66 Gy) were evaluated to assess their impact on BRFS.

Results

The mean patient age in the ART and SRT groups, respectively, was 64 years (range 42–82) and 64.8 years (range 42–82). Median follow-up after RT in the whole sample was 34 months (range 3–141). A total of 702 patients were included: 223 (31.8%) received ART and 479 (68.2%) SRT. BRFS rates (95% CI) in the ART and SRT groups at months 24 and 60 were, respectively: 98.1% (95.9–100.0%) vs. 91.2% (88.2–94.2%) and 84.5% (76.4–92.6%) vs. 74.0% (67.4–80.7%) (p = 0.004). No significant differences in OS were observed (p = 0.053). The following variables were significant predictors of biochemical recurrence in the SRT group: (1) positive surgical margin status (p = 0.049); (2) no hormonotherapy (p = 0.03); (3) total prostate dose ≤66 Gy (p = 0.004); and pre-RT PSA ≥0.5 ng/ml (p = 0.013).

Conclusions

This is the first nationwide study in Spain to evaluate a large cohort of PCa patients treated with RP followed by postoperative RT. ART yielded better 2- and 5-year BRFS rates, although OS was equivalent. These findings are consistent with most other published studies and support ART in patients with adverse prognostic characteristics after radical prostatectomy. Prospective trials are needed to compare immediate ART to early SRT to better determine their relative benefits.

     

Three linked nomograms for predicting biochemical failure in prostate cancer treated with radiotherapy plus androgen deprivation therapy

Background

Nomograms were established to predict biochemical recurrence (BCR) after radiotherapy (RT) with a low weight of the characteristic variables of RT and androgen deprivation therapy (ADT). Our aim is to provide a new stratified tool for predicting BCR at 4 and 7 years in patients treated using RT with radical intent.

Materials and methods

A retrospective, nonrandomized analysis was performed on 5044 prostate cancer (PCa) patients with median age 70 years, who received RT—with or without ADT—between November 1992 and May 2007. Median follow-up was 5.5 years. BCR was defined as a rise in serum prostate-specific antigen (PSA) of 2 ng/ml over the post-treatment PSA nadir. Univariate association between predictor variables and BCR was assessed by the log-rank test, and three linked nomograms were created for multivariate prognosis of BCR-free survival. Each nomogram corresponds to a category of the Gleason score—either 6,7, or 8–10—and all of them were created from a single proportional hazards regression model stratified also by months of ADT (0, 1–6, 7–12, 13–24, 25–36, 36–60). The performance of this model was analyzed by calibration, discrimination, and clinical utility.

Results

Initial PSA, clinical stage, and RT dose were significant variables (p?<?0.01). The model showed a good calibration. The concordance probability was 0.779, improving those obtained with other nomograms (0.587, 0.571, 0.554) in the database. Survival curves showed best clinical utility in a comparison with National Comprehensive Cancer Network (NCCN) risk groups.

Conclusion

For each Gleason score category, the nomogram provides information on the benefit of adding ADT to a specific RT dose.

     

Demand for radiotherapy in Spain

Aim

Assessing the demand for radiotherapy in Spain based on existing evidence to estimate the human resources and equipment needed so that every person in Spain has access to high-quality radiotherapy when they need it.

Material and methods

We used data from the European Cancer Observatory on the estimated incidence of cancer in Spain in 2012, along with the evidence-based indications for radiotherapy developed by the Australian CCORE project, to obtain an optimal radiotherapy utilisation proportion (OUP) for each tumour.

Results

About 50.5 % of new cancers in Spain require radiotherapy at least once over the course of the disease. Additional demand for these services comes from reradiation therapy and non-melanoma skin cancer. Approximately, 25–30 % of cancer patients with an indication for radiotherapy do not receive it due to factors that include access, patient preference, familiarity with the treatment among physicians, and especially resource shortages, all of which contribute to its underutilisation.

Conclusions

Radiotherapy is underused in Spain. The increasing incidence of cancer expected over the next decade and the greater frequency of reradiations necessitate the incorporation of radiotherapy demand into need-based calculations for cancer services planning.