HER2-expressing breast tumors are associated with breast cancer stem-cell phenotype CD44+/CD24-

• Main Authors: Iris Rabinovich (Author), Lúcia de Noronha (Author), Ana Paula M. Sebastião (Author), Rubens S. Lima (Author), Cícero A. Urban (Author), Eduardo Schunemann Jr (Author), Selene Elífio-Esposito (Author), Cleverton C. Spautz (Author), Andréa N. Moreno-Amaral (Author)
• Format: Book
• Published: Sociedade Brasileira de Patologia Clínica, 2018-10-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 1678-4774; 10.5935/1676-2444.20180052
• Keywords: breast neoplasms; neoplastic stem cells; CD44 antigens; CD24 antigens; breast ductal carcinoma; Pathology; RB1-214
• Source: Jornal Brasileiro de Patologia e Medicina Laboratorial, Vol 54, Iss 5, Pp 310-318 (2018)

ABSTRACT INTRODUCTION: According to the cancer stem-cell theory, tumors originate from a small population of cancer stem cells, which lose the mechanism of self-regulation and begin to differentiate and proliferate indefinitely. The CD44+/CD24- phenotype may be considered a stem-cell marker in breast cancer. OBJECTIVE: To evaluate the correlation between CD44+/CD24- phenotype and different molecular subtypes of breast cancer in invasive ductal carcinoma samples. METHODS: The expression of CD44, CD44v6, and CD24 markers was investigated in 133 cases of invasive mammary carcinoma with immunohistochemistry. CD44+/CD24- phenotype was identified and correlated with the molecular subtypes and classical prognostic factors such as age, histological grade, tumor size, and lymph node status. RESULTS: Eighteen (14%) cases were positive for CD44+/CD24- (CD44+/CD24- or CD44v6+/CD24-) phenotype; among these, 11.1%, 27.8%, 38.9%, and 22.2% were luminal, luminal B-human epidermal growth factor receptor 2 (HER2), HER2, and triple-negative subtype, respectively. CD44+/ CD24- phenotype was more common in HER2 subgroup (p = 0.0197). CONCLUSION: CD44+/CD24- phenotype was correlated with molecular subtypes of breast cancer. The highest expression of CD44+/CD24- phenotype was reported in patients with HER2+ disease, a molecular subtype associated with more aggressive behavior and worse prognosis.