Abstract:

INTRODUCTION: Breast cancer is the most common malignancies among women worldwide. Breast cancer is a heterogeneous tumor, with different responses to therapy even within similar histology and stages. In this study we aimed to compare the clinical and pathological features of breast cancer according to the molecular subtypes. METHODS: We retrospectively reviewed the 292 cases with breast cancer, who were diagnosed and treated at the Izmir Tepecik Education and Research Hospital between 2011 and 2014. Descriptive and inferential analyses between different intrinsic subtypes were performed. RESULTS: A total of 292 females with invasive breast cancer were included in this study. The mean age was 55.5±12.8 years (28-85 years) and mean ages of different tumor groups were similar. We identified 90 (30.8%) cases of luminal A, 87 (29.8%) luminal B, 78 (26.7%) HER2+, and 37 (12.7%) triple negative. The mean Ki-67 proliferation index was found 5 (1-12) in Luminal A group, 28.4 (15-80) in Luminal B group, 24.1 (1-95) in Her2 positive group and 43 (1-85) in triple negative group. The mean follow-up was 22.5±10.9 months. Mean mortality rate was found as 10.6% (n = 31) in all patients. The least survival rate was determined in triple negative patients (78.4%, n=29). The highest survival rate was assessed as compatible with the literature in the luminal A group (n= 83, 92.2%). HER2-positive cases had second highest survival rate with tailored treatment (n= 71, 91%). DISCUSSION AND CONCLUSION: Histopathologic features or histological grade of breast cancer alone does not provide reliable prognostic predictions. It must be always considered that breast cancer is a heterogeneous tumor. Therefore in breast cancer, tailored therapy according to the molecular subtypes of tumor, seems to provide the highest benefit for patients.

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