A Comparative Study of the Expression of Her2/Neu in Invasive Ductal Carcinoma of Breast Associated With and Without Ductal Carcinoma in SITU

AIM OF THE STUDY: The clinical outcome of breast carcinoma varies in every individual due to its molecular heterogeneity. Nowadays there is a rising interest whether the associated DCIS in invasive ductal carcinoma of breast affects the prognosis and overall survival of the patient. Only a very few studies has assessed the expression of molecular markers between IDC-DCIS and pure IDC (IDC without DCIS). So the present study was undertaken to study the expression of HER2/neu in invasive ductal carcinoma of breast associated with and without DCIS and also to find the correlation with other clinico-pathological variables with such expression. MATERIALS AND METHODS: Two groups were categorized based on the presence or absence of in situ component in invasive ductal carcinoma of breast. A total of 50 mastectomy specimens were studied for the expression of HER2/neu by IHC, which includes 25 cases of invasive ductal carcinoma associated with DCIS (IDCDCIS) and 25 cases of invasive ductal carcinoma without DCIS (IDC). RESULTS: There is no statistical difference in HER2/neu expression between IDCDCIS and pure IDC (IDC without DCIS). The expression of Ki 67 was significantly higher (p value 0.022) in IDC without DCIS (60%) than IDCDCIS ( 28%).The expression of HER2/neu is associated with large tumor size, positive lymph node status and ER status in IDC without DCIS. Ki 67 which is considered a predictor of chemotherapy is correlated with HER2/neu expression in both the groups but significantly higher in pure IDC (without DCIS). CONCLUSION: IDC associated with DCIS (IDC-DCIS) shows a less malignant behavior compared to IDC without DCIS. Since molecular markers play an important role in tumor carcinogenesis and progression further studies to be done in large scale which might help in identifying the subgroup for targeted therapy