Clinical outcomes of curative-intent multimodal management of chemorefractory nonmetastatic inflammatory breast cancer.

INTRODUCTION: Chemorefractory nonmetastatic inflammatory breast cancer (IBC) which progresses under neoadjuvant chemotherapy poses specific therapeutic challenges: either pursuing a curative-intent treatment with a salvage combination of radiotherapy and surgery or switching to second-line systemic treatments despite the absence of metastasis. Due to the rarity of this situation, no specific management guidelines exist and the outcomes of these patients remain uncertain. In this retrospective observational study, we aimed to report the clinical outcomes of patients treated in a curative intent for chemorefractory nonmetastatic IBC, with a multimodal salvage treatment combining radiotherapy and surgery. MATERIALS AND METHODS: This single-center retrospective observational study included all chemorefractory nonmetastatic IBC treated at the Institut Curie (Paris, France). Overall survival (OS), disease-free survival (DFS), and locoregional relapse-free survival (LRRFS) were calculated from the time of diagnosis and from the time of neoadjuvant chemotherapy interruption. RESULTS: Between January 2010 and January 2018, 7 patients presented with chemorefractory nonmetastatic IBC with a progressive disease during neoadjuvant chemotherapy. Overall, chemorefractory IBC patients were young (median age of 50 years), had a good performance status, and usually presented with node-positive tumors characterized by a combination of adverse histological factors such as triple-negative breast cancer (TNBC), grade III, and high proliferation index. From the date of pathological diagnosis, 1­year OS, DFS, and LRRFS were 64.3%, 53.6%, and 71.4%, respectively. From the date of neoadjuvant chemotherapy interruption, 1­year OS, DFS, and LRRFS were 47.6%, 19.0%, and 45.7%, respectively, and median OS, DFS, and LRRFS were 8.3, 5.0, and 5.0 months, respectively. CONCLUSION: The prognosis of chemorefractory nonmetastatic IBC treated with a multimodal approach combining surgery and radiotherapy is particularly reserved, despite the curative intent of the salvage treatment and the lack of distant metastasis at the time of treatment. Optimal treatment modalities are still to be defined in this rare but critical presentation of IBC.

Radiotherapy in the Management of Non-Metastatic Inflammatory Breast Cancers: A Retrospective Observational Study.

(1) Background: Inflammatory breast cancers (IBC) are characterized by a poor prognosis. This retrospective study aims to describe the clinical outcomes of non-metastatic IBC patients treated with a multidisciplinary approach with neo-adjuvant chemotherapy, surgery, and radiotherapy. (2) Methods: This single-center retrospective study included all women patients diagnosed with non-metastatic IBC between January 2010 and January 2018 at the Institut Curie (Paris, France) and treated with neoadjuvant chemotherapy, surgery, and radiotherapy. Overall survival (OS), disease-free survival (DFS), and locoregional free survival (LRRFS) were calculated from the time of diagnosis. Prognostic factors for patient survival were analyzed based on univariate and multivariate regressions. (3) Results: We identified 113 patients with a median age of 51 years. 79.7% had node-positive tumors; triple-negative breast cancers (TNBC) represented 34.6% of the cases. A large majority of patients (91.2%) received adjuvant post-mastectomy while ten patients (8.8%) received preoperative radiotherapy. Non-pathological complete response (non-pCR) was observed in 67.3% of patients. Radiotherapy delivered a median dose of 50 Gy to the breast or the chest wall in 25 fractions. With a median follow-up of 54 months, 5-year OS, DFS and LRRFS were 78% (CI: 70.1-86.8%), 68.1% (59.6-77.7%), and 85.2% (78.4-92.7%), respectively. In multivariate analysis, non-pCR was an adverse prognosis factor for OS, DFS, and LRRFS; pre-operative radiotherapy was an adverse prognosis factor for OS and DFS. Radiation-related adverse events were limited to acute skin toxicity (22% of Grade 2 and 2% of grade 3 dermatitis); no late radiation-induced toxicity was reported. (4) Conclusions: High locoregional control could be achieved with multidisciplinary management of non-metastatic IBC, suggesting the anti-tumor efficacy of radiotherapy in this rare but pejorative clinicopathological presentation. While comparing favorably with historical cohorts, OS and DFS could be potentially improved in the future with the use of new systemic treatments, such as PARP-inhibitors or immunotherapy.