Immunohistochemical Study of MUC1, MUC2 and MUC5AC Expression in Primary Breast Carcinoma.

Introduction: Breast Cancer (BC) is the second most common cancer among women in India and accounts for 7% of global burden of BC and one-fifth of all Cancers (CA) among women in India.
Aim: This study was conducted for studying the expression of MUC1, MUC2 and MUC5AC in breast carcinoma.
Materials and Methods: Fifty cases of primary breast carcinoma diagnosed between years 2013 to 2015 were included in the study. Manual tissue array technique was applied for cases subjected to Immunohistochemistry (IHC). An analysis of the expression of IHC markers (MUC1, MUC2, MUC5AC, ER, PR and HER2/neu) was attempted. Results were subjected to statistical analysis. They were considered to be significant when the p-value was less than 0.05.
Results: The positivity for MUC1, MUC2 and MUC5AC in BC was 58%, 8% and 6% and for ER, PR and HER2 was 48%, 36% and 64% respectively. There was a significant correlation between MUC1 expression and ER and PR positivity. There was a significant correlation between MUC2 expression and ER positivity. No significant association was observed between MUC2 and PR expression, MUC5AC expression and ER and PR positivity. There was statistically significant correlation between negative MUC2 and MUC5AC expression and histopathological grade. It was noted that MUC2 and MUC5AC negative tumours were associated with higher tumour stage though not statistically significant. It was noted that MUC5AC negative tumours showed higher frequency of lymphovascular invasion though not statistically significant.
Conclusion: Our experience with the present study highlights the role of mucins in the development and progression of BC.