ABS ePoster Library

P026
Topic: Basic science

Introduction: 20-25% of breast cancer in developing countries present with skin involvement. The challenge in them is to achieve adequate down-sizing and R0 resection. Apart from 10% of patients which shows scattered cytoreduction, a large group show differential response pattern at the surface (skin) and in the parenchyma.AimsTo study the post-NACT disease pattern in surface and core of the lesion histopathologically and correlate the results with cancer stem cell distribution.Methodology18 patients with post NACT T4b lesions were included in the study. Tissue was taken from the skin zone and core of the tumour. The tissues were studied histopathologically with reference to density of malignant cells (>3 clumps), tubule formation, nuclear pleomorphism ,mitotic score, TILs and vascular density at the periphery. The results were analysed using t-test (first three) or chi-square (last three) using SPSS-version24.0. ALDH1 (surrogate CSC marker)expression of different areas was assessed.ResultMalignant cell-density (p 0.023), mitotic score(p 0.0184),nuclear pleomorphism( p 0.0290)and vascular congestion (p 0.0233) was significantly more persistent after chemotherapy at the dermal component while TILs(p 1.0) and tubule formation(p 0.25) was insignificant. ALDH 1 expression was significantly (p 0.023) more in chemoresistant areas.DiscussionBreast cancer is less sensitive to NACT once there is gross skin involvement. The disease shows a heterogenous response. This is because of the linear migration of cancer stem cells from core area to the surface. Study of T4 lesions offers opportunity for study of heterogeneous nature of breast cancer.