Immunohistochemical analysis of CD9, CD29 and epithelial to mesenchymal transition in triple-negative breast cancer.

ABSTRACT

BACKGROUND: Triple-negative breast carcinomas (TNBC) are a heterogeneous group of tumors with mostly aggressive behaviour and poor prognosis. In association with their aggressive behavior and chemoresistance to treatment, the concept of epithelial-mesenchymal transition (EMT) has come to the fore. CD9 and CD29 proteins are associated with EMT and may play a role in TNBC progression. Our aim was to investigate association of these markers with the lymph node metastasis, tumor grade, proliferative activity, and patient survival. PATIENTS AND METHODS: Our cohort consisted of 66 TNBC patients without neoadjuvant therapy, aged 26-81 years. The pathological tumor stages ranged from pT1b to pT3 and histological grades ranged from II to III, according to the Bloom-Richardson system. Immunohistochemical evaluation of CD9, CD29, E-cadherin, vimentin, androgen receptor and Ki-67 expression was performed semiquantitatively using the H-score. Expression of the proteins was statistically evaluated in relation to the clinicopathological parameters and survival of the patients. RESULTS: We observed lower expression of CD9 in lymph node metastases compared to the primary tumor (P = 0.021). The CD29 expression in primary tumor was significantly lower in patients with lymph node metastases compared to patients without cancer dissemination (P = 0.03). Neither CD9 nor CD29 protein expression was associated with breast cancer-specific survival (BCSS). Lower expression of E-cadherin at the periphery of the primary tumor was associated with worse BCSS (P = 0.038). Neither grade nor the presence of lymph node metastases reached significant association with the BCSS. Lower expression of E-cadherin at the periphery was also associated with higher Ki67 (Rs -0.26) and vimentin (Rs -0.33). CONCLUSION: Decreased protein expression of CD9 and CD29 were associated with lymph node metastasis growth, however, their association with survival was not proved. Lower expression of E-cadherin at the periphery of the primary tumor was associated with high proliferation and poor breast cancer-specific survival.