Background and aims: Clinicopathological features of Basal-like Breast Cancer (BLBC) in African American women have been extensively studied. Comparatively, less is known about these tumors in patients from countries in the North African region. The aim of this study was to assess the frequency and clinicopathological characteristics of BLBC in Egyptian patients with comparison to British patients.
Material and methods: Tissue microarray blocks were constructed from primary invasive breast cancer from 321 Egyptian and 527 British BC patients. Sections were stained immunohistochemically with oestrogen receptor (ER), progesterone receptor (PR), HER2, CK19, CK14, EGFR, CK5/6, P53 and Ki67. BLBC phenotype was identified by lacking of staining of ER, PR, HER2 and positive staining for any of the CK14, CK5/6 and/or EGFR. Results: The rate of BLBC phenotype was higher in Egyptian cohort (21%) than the British cohort (13%). BLBC tumors from both Egyptian and British patients were significantly associated with tumors of higher histopathological grade (P<0.001& P<0.001), higher proliferation rate (P<0.001& P=0.001), and higher rate of P53 expression (P<0.001& P<0.001) respectively. Compared with the British tumors, BLBC in Egyptian women were significantly of larger tumor size (P<0.001) and were associated with more advanced lymph node (LN) stage (P<0.001).
Conclusion: BLBC occurred more frequently in Egyptian patients compared with British women and are characterized by unfavorable biological features akin to BLBC in African American women. These warrant further studies to unravel the genetic background of BLBC and whether their aggressive features are related to ethnic origin or other multi-factorial and environmental variables.