Is Metaplastic Breast Cancer that rare? We all want to know!
I loved this abstract of an article I found from the ASCO conference. It talks about how Metaplastic Breast Cancer (MBC) is often confused with IDC.
The exact quote is below:
Background: Metaplastic breast cancer (MBC) is a malignancy characterized by the histologic presence of two or more cellular types. MBC is rare relative to invasive ductal carcinoma (IDC), representing less than 1% of all breast cancers. However, since it presents a “triple-negative” (TN) immunohistochemistry feature, MBC may be mistakenly reported as IDC, which may have important consequences on management and outcomes. Methods: A retrospective analysis of patients with final diagnosis of MBC was conducted. The aim was to compare the initial diagnosis, usually from community pathology services, with the final pathology report from certified pathology service. Results: From January 2008 to January 2014, there were 17 consecutive female patients diagnosed with MBC. Median age was 49 years-old (range 26-80), and 47% were above 50 years-old. About 52.9% had a tumor size less than 3 cm, and 35.2% from 3.1 cm to 6 cm. Immunohistochemistry for Ki67 was > 14% in 100% of tissue samples. Most patients had no axillary lymphadenopathy at diagnosis (76.4%), and none of them had distant metastases at presentation. Seven patients (40%) had initial diagnosis of triple-negative IDC from community pathology services. Interestingly, 3 out of 5 patients that were initially treated with neoadjuvant chemotherapy for IDC presented major disease progression during the first cycles and pathology review was requested changing the diagnosis to MBC. Conclusions: Due to the triple-negative histopathologic features, metaplastic breast cancer has been underdiagnosed by community pathology services and may not be as rare as reported. Since triple-negative IDC patients that undergo neoadjuvant chemotherapy usually present high response rates, in cases of no response or disease progression MBC diagnosis should be considered and pathology report must be reviewed.
Thanks to these fantasic doctors and researchers for finding out about us!
Author(s): Carina Meira Abrahao, Andrea Malta Ferrian, Jessica Ribeiro Gomes, Giselle Almeida, Aline Rocha Lino, Tercia Tarciane Souza, Marcelo Rocha Cruz; Centro Oncologico Antonio Ermirio Moraes, Sao Paulo, Brazil; Cento Oncologico Antonio Ermirio Moraes, Sao Paulo, Brazil; Centro Oncologico Antônio Ermínio de Moraes, Sao Paulo, Brazil; Hospital São José, São Paulo, Brazil; Centro Oncologico Antonio Ermirio de Moraes, São Paulo, Brazil