Expression of Her-2 and Ki-67 in Gastric Cancer Formalin Fixed Paraffin Embedded Tissue Blocks and Their Correlation with Histological Grades at the Uganda Cancer Institute Pathology Laboratory

Hassan Wasswa,1,2 Abraham Birungi,3 Lawrence Amadile,1 Richard Kasadha,1 Saphurah Nabaasa,1 Jolly Lydia Ninsiima,1 Tonny Okecha,2 Frank Ssedyabane,1 Raymond Atwine,3 Lauben Tibenderana1 1Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda; 2Department of Pathology and Laboratory Medicine, Uganda Cancer Institute, Kampala, Uganda; 3Department of Pathology, Faculty of Medicine; Mbarara University of Science and Technology, Mbarara, UgandaCorrespondence: Hassan Wasswa, Department of Medical Laboratory Science; Faculty of Medicine, Mbarara University of Science of Science and Technology, Mbarara, P.O. Box 1410, Uganda, Tel +256-752992310, Email [email protected]: Her-2/neu, the human epidermal growth factor receptor-2, is an oncogene reported to be excessively expressed in gastric cancer. This over-expression is a criteria for treatment with trastuzumab. An antigen linked to nuclear proliferation is Ki-67, and the level of gastric cancer aggression is reflected in its expression.Objective: To determine the expression of Her-2 and Ki-67 in gastric cancer formalin-fixed paraffin-embedded (FFPE) tissue blocks and their correlation with histological grades at the Uganda Cancer Institute pathology laboratory, with each block representing one gastric cancer case.Methods: A laboratory cross-sectional study was conducted among 75 endoscopic gastric cancer patient cases. Each case was assessed utilizing immunohistochemistry (IHC) for the expression of Her-2 and Ki-67. Spearman correlation coefficient was used to ascertain the expression and its correlation to histological grades.Results: The age range of gastric cancer cases was 26 to 80 years, with a mean age of 54. Poorly differentiated histology (43%) was the most profound. Her-2 over-expression was 20%. High Ki-67 expression was 56%, and the low Ki-67 expression was 7%. Her-2 overexpression correlated significantly with moderate differentiation (rs = 0.336, p = 0.003) and poor differentiation (rs = − 0.229, p = 0.048). A significant correlation between moderate differentiation of gastric carcinoma with low intensity of Ki-67 staining was noted (rs = 0.255, p = 0.028).Conclusion: The aggressiveness of gastric cancer may be indicated by the over-expression of Her-2 and a high Ki-67.What This Study Adds: This study provides additional information on the relevance of Her-2 and a high Ki-67 over-expression in diagnosis, prognostic monitoring, and management of gastric cancer in Uganda.Keywords: human epidermal growth factor receptor 2, immunohistochemistry, nuclear proliferation-associated antigen, histology grade