Immunohistochemical signaling pathways of triple negative and triple positive breast cancers: What is new?

• Published in: Annals of diagnostic pathology 2021-12, Vol.55, p.151831-151831, Article 151831
• Main Authors: Elsers, Dalia A., Masoud, Eman Mostafa, Kamel, Nermeen A.M.H., Ahmed, Asmaa M.
• Format: Article
• Language: English
• Subjects: Adult; Androgen receptor; Breast cancer; Breast Neoplasms - metabolism; c-Myc; DNA-Binding Proteins - metabolism; Female; HER2; Humans; Immunohistochemistry; Middle Aged; Prognosis; Receptors, Androgen - metabolism; Signal Transduction; Transcription Factors - metabolism; Treatment Outcome; Triple Negative Breast Neoplasms - metabolism
• ISSN: 1092-9134; 1532-8198
• DOI: 10.1016/j.anndiagpath.2021.151831

Breast cancer (BC) is a heterogeneous disease with different clinically heterogeneous phenotypes. Triple negative BC (TNBC) (ER-/PR-/HER2-) and triple positive BC (TPBC) (ER+/PR+/HER2+) are characterized by unique clinical behavior and therapeutic challenges. However, their exact molecular pathogenesis is not well studied. This study aims to evaluate the immunohistochemical expression of androgen receptor (AR) and c-Myc in TPBCs and TNBCs, correlate their expression with the clinicopathologic features, and assess the correlation between AR and c-Myc expression in TPBCs and TNBCs. AR and c-Myc were immunohistochemically assessed in 45 TNBC and 15 TPBC specimens. AR expression was detected in 17.7% of TNBC and in all TPBC specimens. c-Myc was expressed in 46.7% of TNBC and in all TPBC specimens. AR and c-Myc expression in TNBC was not associated with any of the clinicopathological features. In TPBC, AR expression was higher in older age, larger size, higher stage, and lymph node metastasis while c-Myc expression was higher in tumors with perineural invasion. This is the first study that reported a significant positive correlation between AR and c-Myc expression in TNBC and TPBC. The current results suggested that AR and c-Myc proteins may contribute to the pathogenesis of TNBC and TPBC. The positive correlation between the two proteins in these subtypes sheds new light on a distinct pathway by which BC cells can modulate their proliferation. Targeting both molecules may provide new therapeutic approaches to improve therapeutic sensitivity and patients' outcomes of these subtypes. •AR was detected in 17.7% of TNBC and in all TPBC specimens.•c-Myc was expressed in 46.7% of TNBC and in all TPBC specimens.•Correlation between AR and c-myc expression may provide a distinct pathway that modulates BC cells proliferation.