Hypofractionated whole breast irradiation in women less than 50 years old treated on four prospective protocols
Menée à partir de données portant sur 348 patientes âgées de moins de 50 ans et atteintes d'un cancer du sein traité entre 2003 et 2015 (durée médiane de suivi : 67 mois), cette étude évalue l'intérêt, du point de vue des taux de survie et des résultats esthétiques, d'une radiothérapie hypofractionnée de l'ensemble du sein après une chirurgie conservatrice
Background : Hypofractionated whole breast radiation (RT) has proven to be equivalent to conventionally fractionated RT in multiple randomized trials. There is controversy regarding its use in younger women due to their underrepresentation in trials and concern for late toxicity. We evaluate disease control and cosmetic outcomes in patients age < 50 treated with hypofractionated RT on 4 prospective single-institutional trials. Methods : From 2003-2015, 1313 patients were enrolled in 4 prospective protocols investigating the use of adjuvant hypofractionated RT after breast conserving surgery with a daily or weekly concomitant boost. We identified 348 patient records age < 50 at consultation for this analysis. Overall survival (OS), Disease free survival (DFS), and Local recurrence free survival (LRFS) were estimated using the Kaplan Meier method by study and across studies using meta-analytic methods. Late effects of radiation, clinician rated cosmesis and patient rated cosmesis were also evaluated. Results : With a median follow up of 66.9 months, OS was 99.6%, DFS was 96.3% and LRFS was 97.7% at 3 years. Clinician rated cosmesis (n=242) was 93.4% excellent or good, 6.6% fair or poor. Patient rated cosmesis (n=259) was 86.1% excellent or good, 13.9% fair or poor. Of the patients who rated themselves differently than their physicians, patients more often rated themselves poorly compared to their physician (Cochran-Mantel-Haenszel p-value = 0.0044). Conclusions : At a median follow up of 5 years, an analysis of patients < 50 demonstrates that hypofractionated radiation was safe and effective, with good to excellent cosmesis as assessed by both clinicians and patients.