Audree B Tadros1, Varadan Sevilimedu2, Dilip D Giri3, Emily C Zabor2,4, Monica Morrow1, George Plitas5. 1. Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. 2. Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA. 3. Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA. 4. Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio, USA. 5. Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. plitasg@mskcc.org.
Abstract
BACKGROUND: Metaplastic breast carcinoma (MBC) is a rare, aggressive subtype of breast cancer associated with poorer overall survival than other triple-negative breast cancers. This study sought to compare survival outcomes among histologic subtypes of MBC with those of non-metaplastic triple-negative breast cancer. METHODS: Clinicopathologic and treatment data for all patients with non-metastatic, pure MBC undergoing surgery from 1995 to 2017 and for a large cohort of patients with other types of triple-negative breast cancer during that period were collected from an institutional database. The MBC tumors were classified as having squamous, spindle, heterologous mesenchymal, or mixed histology. Survival outcomes were compared using the Kaplan-Meier method. RESULTS: Of 132 MBC patients, those with heterologous mesenchymal MBC (n = 45) had the best 5-year overall and breast cancer-specific survival (BCSS, 88%; 95% confidence interval [CI], 0.78-0.99), whereas those with squamous MBC had the worst survival (BCSS, 56%; 95% CI, 0.32-0.79). Overall survival, BCSS, and recurrence-free survival were worse for the patients with MBC than for the patients who had non-MBC triple-negative breast cancer, with a clinicopathologically adjusted recurrence hazard ratio of 2.4 (95% CI, 1.6-3.3; p < 0.001). Of the 10 MBC patients who received neoadjuvant chemotherapy, 4 progressed while receiving treatment, and 3 had no response. CONCLUSIONS: Metaplastic breast carcinoma is associated with worse survival than other triple-negative breast cancers. The heterologous mesenchymal subtype is associated with the best survival, whereas the squamous subtype is associated with the worst survival. These data call for research to identify therapies tailored to MBC's unique biology.
BACKGROUND: Metaplastic breast carcinoma (MBC) is a rare, aggressive subtype of breast cancer associated with poorer overall survival than other triple-negative breast cancers. This study sought to compare survival outcomes among histologic subtypes of MBC with those of non-metaplastic triple-negative breast cancer. METHODS: Clinicopathologic and treatment data for all patients with non-metastatic, pure MBC undergoing surgery from 1995 to 2017 and for a large cohort of patients with other types of triple-negative breast cancer during that period were collected from an institutional database. The MBC tumors were classified as having squamous, spindle, heterologous mesenchymal, or mixed histology. Survival outcomes were compared using the Kaplan-Meier method. RESULTS: Of 132 MBCpatients, those with heterologous mesenchymal MBC (n = 45) had the best 5-year overall and breast cancer-specific survival (BCSS, 88%; 95% confidence interval [CI], 0.78-0.99), whereas those with squamous MBC had the worst survival (BCSS, 56%; 95% CI, 0.32-0.79). Overall survival, BCSS, and recurrence-free survival were worse for the patients with MBC than for the patients who had non-MBC triple-negative breast cancer, with a clinicopathologically adjusted recurrence hazard ratio of 2.4 (95% CI, 1.6-3.3; p < 0.001). Of the 10 MBCpatients who received neoadjuvant chemotherapy, 4 progressed while receiving treatment, and 3 had no response. CONCLUSIONS: Metaplastic breast carcinoma is associated with worse survival than other triple-negative breast cancers. The heterologous mesenchymal subtype is associated with the best survival, whereas the squamous subtype is associated with the worst survival. These data call for research to identify therapies tailored to MBC's unique biology.
Authors: Willard Wong; Edi Brogi; Jorge S Reis-Filho; George Plitas; Mark Robson; Larry Norton; Monica Morrow; Hannah Y Wen Journal: NPJ Breast Cancer Date: 2021-07-22