Stereotactic radiotherapy for localized prostate cancer: 10-year outcomes from three prospective trials
Menée auprès de 267 patients atteints d'un cancer de la prostate de stade localisé et inclus dans 3 essais cliniques canadiens entre 2006 et 2013 (durée médiane de suivi : 10,3 ans), cette étude analyse l'efficacité, du point de vue de la survie globale et du taux de récidive biochimique, d'une radiothérapie stéréotaxique d'ablation
Résumé en anglais
Background and purpose: Stereotactic ablative radiotherapy (SABR) is growingly accepted for the treatment of localized prostate cancer with recent randomized trials showing non-inferiority compared to conventional or moderately hypofractionated radiotherapy. The natural history of prostate cancer necessitates extended surveillance for recurrence; however, there are few prospective studies reporting long-term outcomes.
Materials and methods: This study included patients with low and intermediate risk localized prostate cancer from three Canadian clinical trials enrolled from 2006-2013. All patients received SABR to the prostate consisting of 35-40 Gy in 5 fractions over 11-29 days. PSA, distant metastasis, and vital status were prospectively recorded. Occurrence of second malignancy after treatment was assessed by chart review and classified using modified Cahan's criteria.
Results: 267 patients were included. Median follow up was 10.3 years (IQR 7.8 – 12.7). 10-year BF (95% CI) was 7.7% (3.9-11.5). 10-year OS, PCSS, and FFM were 84.1% (79.3 – 89.1%), 99.2% (98.1 – 100), and 98.8% (97.5-100), respectively. 27/267 (10.1%) patients experienced a SM, with 6/27 patients (22.2%) classified as having a SM likely (n=3) or possibly (n=3) related to prior radiotherapy. 10-year freedom from SM was 89.2%.
Conclusion: SABR shows excellent long-term disease control for low and intermediate risk localized prostate cancer. Patients treated for prostate cancer have a moderate risk of second malignancy, consistent with background rates for the population.
