Local Relapse after Breast Conserving Therapy vs. Mastectomy for Extensive Pure Ductal Carcinoma In-Situ ≥4 cm
Menée auprès de 720 patientes atteintes d'un carcinome canalaire in situ de taille supérieure ou égale à 4 cm et diagnostiqué entre 1989 et 2010, cette étude compare, du point de vue de la récidive locale à 10 ans, l'efficacité d'une mastectomie et d'une chirurgie conservatrice en combinaison ou non avec une radiothérapie
Purpose : The optimal treatment for patients with extensive pure DCIS ≥4 centimeters (cm) is controversial. This study evaluates local relapse according to type of local therapy: mastectomy, breast conserving surgery (BCS) alone, and BCS + radiotherapy. Materials and Methods : Subjects were female patients diagnosed between 1989 and 2010 with pure DCIS ≥4 cm referred to our institution. Clinicopathologic and treatment characteristics were compared between treatment cohorts. Local relapse (LR) was estimated using competing risk analysis. Multivariable analysis (MVA) was performed using Cox regression analysis. Results : Patients had the following treatments: 490 mastectomy, 38 BCS alone, 192 BCS + radiotherapy. The ten-year cumulative incidence of LR was 16% after BCS (95% CI 6-29%), 8% after BCS + radiotherapy (95% CI 4-12%) and 2% after mastectomy (95% CI 1-4%). On MVA, estrogen receptor-negative disease (HR 3.32, 95% CI 1.08-10.18, p=0.04) and positive margins (HR 3.55, 95% CI 1.56—8.05, p=0.002) were associated with increased LR. BCS alone (HR 7.87, 95% CI 2.82-21.92, p<0.0001), BCS + radiotherapy + no boost (HR 3.80, 95% CI 1.56-9.28, p=0.003) and BCS + radiotherapy + boost (HR 5.76, 95% CI 2.59-12.83, p<0.0001) were all associated with a higher risk of relapse relative to mastectomy. Conclusions : Mastectomy remains a standard local treatment option for extensive DCIS, but BCS + radiotherapy may also be reasonably considered in selected patients with a careful discussion of the benefits, side effects, and patient preferences.