The immunohistochemical expression of the oestrogen receptor (ER), HER-2/NEU and cytokeratin 8/18 and 5/6 in invasive breast carcinoma

Introduction: Carcinoma is the most common malignancy of the breast and breast cancer is the most common non-skin malignancy in women. Ideally, prevention or very early detection of breast cancer reduce both morbidity and mortality of the disease. Effective use of tumour markers might permit the application of screening and treatment more efficiently. Materials and Methods: Immunohistochemical study was done in 39 cases of invasive breast carcinoma for further sub- classification for predicting prognosis and therapeutic approach. The cases were evaluated for expression of cytokeratin Ck 8/18, ER & Her-2/neu and 28 cases were subjected to cytokeratin Ck 5/6 including especially the cases negative for all the three markers. Results: ER was positive in seven cases with Her-2/neu being positive in eight cases and cytokeratin 8/18 positive in 33 cases. Cytokeratin 5/6 was positive in seven cases with four cases showing Ck 5/6 and Ck8/18 positivity, three cases showing positivity for Ck 5/6 only and three cases were negative for all the four markers. Conclusion: Thus classifying them to be luminal A, luminal B, combined, basal and null type respectively. Luminal A tmours show the best prognosis while luminal B tumours, combined, basal and null type are associated with less favouable outcome. Thus it is important to categorise them according to the cell of origin for prognosis and treatment.