Once-Daily Radiation Therapy for Inflammatory Breast Cancer
Menée sur 52 patientes atteintes d'un cancer inflammatoire non métastatique du sein traité entre 2000 et 2010 (âge : 23 à 83 ans ; durée médiane de suivi : 5 ans), cette étude rétrospective évalue l'efficacité, du point de vue du contrôle locorégional, de la survie sans maladie et de la survie globale, et la toxicité d'une radiothérapie à forte dose quotidienne de rayonnements (1,8 à 2,25 Gy pour une dose totale délivrée de 46 à 56,25 Gy) après une mastectomie avec ou sans chimiothérapie adjuvante
Résumé en anglais
Purpose : Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer variant treated with multimodality therapy. A variety of approaches intended to escalate the intensity and efficacy of radiation therapy have been reported, including twice-daily radiation therapy, dose escalation, and aggressive use of bolus. Herein, we examine our outcomes for patients treated with once-daily radiation therapy with aggressive bolus utilization, focusing on treatment technique.
Methods and Materials : A retrospective review of patients with nonmetastatic IBC treated from January 1, 2000, through December 31, 2010, was performed. Locoregional control (LRC), disease-free survival (DFS), overall survival (OS) and predictors thereof were assessed.
Results : Fifty-two women with IBC were identified, 49 (94%) of whom were treated with neoadjuvant chemotherapy. All underwent mastectomy followed by adjuvant radiation therapy. Radiation was delivered in once-daily fractions of 1.8 to 2.25 Gy (median, 2 Gy). Patients were typically treated with daily 1-cm bolus throughout treatment, and 33 (63%) received a subsequent boost to the mastectomy scar. Five-year Kaplan Meier survival estimates for LRC, DFS, and OS were 81%, 56%, and 64%, respectively. Locoregional recurrence was associated with poorer OS (P<.001; hazard ratio [HR], 4.1). Extracapsular extension was associated with worse LRC (P=.02), DFS (P=.007), and OS (P=.002). Age greater than 50 years was associated with better DFS (P=.03). Pathologic complete response was associated with a trend toward improved LRC (P=.06).
Conclusions : Once-daily radiation therapy with aggressive use of bolus for IBC results in outcomes consistent with previous reports using various intensified radiation therapy regimens. LRC remains a challenge despite modern systemic therapy. Extracapsular extension, age ≤50 years, and lack of complete response to chemotherapy appear to be associated with worse outcomes. Novel strategies are needed in IBC, particularly among these subsets of patients.
