Breast-Conserving Treatment With or Without Radiotherapy in Ductal Carcinoma In Situ: 15-Year Recurrence Rates and Outcome After a Recurrence, From the EORTC 10853 Randomized Phase III Trial
Mené sur 1 010 patientes atteintes d'un carcinome canalaire in situ traité par exérèse locale entre 1986 et 1996 (durée médiane de suivi : 15,8 ans), cet essai randomisé de phase III évalue, du point de vue de la récidive locale et de la survie globale, l'intérêt d'ajouter une radiothérapie adjuvante au traitement
Purpose : Adjuvant radiotherapy (RT) after a local excision (LE) for ductal carcinoma in situ (DCIS) aims at reduction of the incidence of a local recurrence (LR). We analyzed the long-term risk on developing LR and its impact on survival after local treatment for DCIS. Patients and Methods : Between 1986 and 1996, 1,010 women with complete LE of DCIS less than 5 cm were randomly assigned to no further treatment (LE group, n = 503) or RT (LE+RT group, n = 507). The median follow-up time was 15.8 years. Results : Radiotherapy reduced the risk of any LR by 48% (hazard ratio [HR], 0.52; 95% CI, 0.40 to 0.68; P < .001). The 15-year LR-free rate was 69% in the LE group, which was increased to 82% in the LE+RT group. The 15-year invasive LR-free rate was 84% in the LE group and 90% in the LE+RT group (HR, 0.61; 95% CI, 0.42 to 0.87). The differences in LR in both arms did not lead to differences in breast cancer–specific survival (BCSS; HR, 1.07; 95% CI, 0.60 to 1.91) or overall survival (OS; HR, 1.02; 95% CI, 0.71 to 1.44). Patients with invasive LR had a significantly worse BCSS (HR, 17.66; 95% CI, 8.86 to 35.18) and OS (HR, 5.17; 95% CI, 3.09 to 8.66) compared with those who did not experience recurrence. A lower overall salvage mastectomy rate after LR was observed in the LE+RT group than in the LE group (13% v 19%, respectively). Conclusion : At 15 years, almost one in three nonirradiated women developed an LR after LE for DCIS. RT reduced this risk by a factor of 2. Although women who developed an invasive recurrence had worse survival, the long-term prognosis was good and independent of the given treatment.