Metaplastic breast cancer: A retrospective analysis over 14 years.

Abstract

e13066 Background: Metaplastic breast carcinoma (MBC), a rare entity, is known to be an aggressive form of breast cancer. With few published reports and scant literature, there are no current guidelines for this type of cancer. The aim of the study is to describe the patient characteristics, pathologic features, treatment and clinical outcomes of the patients with MBC at our institution. Methods: A retrospective analysis of patient charts with histologically confirmed MBC from 2001 to 2014 was done. Clinical information was abstracted from the medical records. Medical records were reviewed for patient age, tumor size, nodal status, tumor grade, hormone receptor status, treatment, recurrence rates and survival characteristics. Results: Twenty-three patients were identified with a median age at diagnosis of 59 years (range 42-91 years). The median tumor size was 2.1 cm (range 0.4-4.5 cm). Most tumors were grade 3 (73.9 %). None of the patients had metastatic disease at presentation. 17 patients were node negative (74%). 13 patients (56.5 %) were triple negative. 6 patients (26 %) underwent mastectomy and 17 underwent lumpectomy. 16 out of 23 patients underwent post-operative radiation therapy. The 5-year disease free survival was 73.9 % and 5-year overall survival was 82.6%. The tumor size was more than or equal to 2.4 cm in all the patients with recurrence. 60 % of the patients with recurrence were triple negative and 20% were Her2 neu positive. 33.33 % patients were poorly differentiated on histology. Conclusions: Based on our analysis and review of literature, MBC has higher tumor grade, hormone receptor negativity and lesser nodal involvement on presentation. Various studies have shown that tumor size is often large on presentation. In our study, tumor size was modest on presentation. Hence, our survival rates are better than seen with other studies. As per our analysis and as demonstrated by other studies, tumor size is an independent risk factor for recurrence. Other ominous factors for recurrence are triple negative hormone status and poorly differentiated tumor as seen in our case. Further studies and clinical trials comparing with infiltrating ductal carcinoma are needed to understand this rare breast cancer.