Background: Gastrointestinal tract (GIT) cancers have a varied presentation and different prognosis for similarly staged disease. In addition to breast carcinoma, overexpression of components of the HER signalling pathway have been associated with poor outcomes and a more aggressive disease even in primary GIT cancers. To evaluate the utility of EGFR and HER-2/Neu immunoexpression pattern in various primary GIT malignancies as surrogate genetic prognostic markers in comparison to convention histological parameters. Methods: A retrospective analysis of formalin fixed, paraffin embedded (FFPE) sections of tumour tissue from 30 GIT resection specimen were done. EGFR and HER2/Neu immunoexpression were evaluated against the histological grade and stage of the tumour. Result: In the study population the mean age was 58.4 years. Adenocarcinoma constituted 80% cases, with 73.33% being moderately differentiated. T3 tumours (60% cases) were the most frequently encountered malignancy. Lymphovascular invasion was seen in 13.33% while nodal positivity was noted in 64.29% cases. HER2 overexpression was seen in three cases (10%) of oesophageal squamous cell carcinoma while EGFR overexpression was found in four cases (13.33%). Overall, cases showing EGFR and HER-2 overexpression were mostly of the elderly age group, oesophageal squamous carcinomas, were T2/T3 in size and with nodal involvement. Conclusion: EGFR and HER2 have a valuable role as ancillary prognostic markers in GIT malignancies. However standardization of EGFR and HER2 testing procedures along with careful interpretation are essential steps to ensure accurate, reproducible and optimal results.

Keywords: EGFR; Genetic prognostic factors; GIT malignancies; HER-2.