Immunohistochemical Evaluation of Alpha-Methyl Acyl CO-A Racemase Expression in Gastric Biopsies and Resected Specimens with Histopathological Correlation

Mirunalini, K A T (2020) Immunohistochemical Evaluation of Alpha-Methyl Acyl CO-A Racemase Expression in Gastric Biopsies and Resected Specimens with Histopathological Correlation. Masters thesis, Stanley Medical College, Chennai.


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INTRODUCTION: Gastric cancer is the third leading cause of cancer deaths worldwide and has the fifth highest incidence of cancer worldwide with incidence among other cancers being 5.2%. In India gastric carcinoma accounts for fifth and seventh most common cancer in male and female respectively and second most common cause of death due to cancer. There is plenty of genetic alteration that occurs in gastric adenocarcinoma that operates through various pathways like mTOR pathway, Ras/Raf/Kinase pathway. Since AMACR is one of the many enzymes involved in regulation of mTOR pathway implicated in gastric cancer the present study was planned to determine if AMACR can be used as a diagnostic marker in gastric adenocarcinoma similar to prostate cancer. AIM AND OBJECTIVES: The aims and objectives are to differentiate neoplastic and non-neoplastic lesions by histopathological examination; to observe the expression of AMACR in both neoplastic and non-neoplastic lesions; to examine the rate of positivity and negativity in all the lesions; to correlate the expression of AMACR in various grades of adenocarcinoma. Aim is also to determine whether these results are statistically significant. MATERIALS AND METHODS: This study is a prospective and retrospective study of two years from July 2017 to July 2019. A total of 60 cases received in the Dept of Pathology, Govt. Stanley Medical College were studied. The tissues were fixed in 10% neutral buffered formalin. Tissues were processed and paraffin wax embedded. All the cases were stained with H and E and typing according to WHO classification. All these cases where studied for AMACR expression. Statistical analysis was done by Chi square test (SPSS.v23) and P value of ≤0.05 was considered to be significant. RESULTS: 60 cases of gastric samples were examined consisting 14(23.3%) cases of Gastritis, 2 cases (3.3%) of Dysplasia and 44(73.4%) cases of Gastric carcinoma. Most common age group of total cases was 41-50 years. Male to female ratio was 1.7:1. AMACR expression was positive in 1 case (7.1%) of gastritis and negative in remaining 13 cases. In dysplasia group, AMACR was positive in 1 case (50%). Among 44 cases of adenocarcinoma, AMACR expression was seen in 21 cases. Out of 21 cases, 15/21 belonged to less than 60 years age group whereas 6/21 belonged to more than 60 years. Statistical significance was not present as showed by p value of 0. 1117.AMACR expression was seen in 14 (66.7%) males and 7 females showed positive expression for AMACR (33.3%). But this difference was not statistically significant (p value – 0.83491) Of the total 44 cases of gastric adenocarcinoma, 34 cases (77.3%) belonged to intestinal type and 10 cases (22.7%) were of diffuse/ signet ring cell type of adenocarcinoma. Out of 34 cases of intestinal type of adenocarcinoma, 17 (50%) showed AMACR expression and 4(40%) out of 10 cases of diffuse type of adenocarcinoma showed positive expression. Grade wise distribution of adenocarcinoma included, 9 cases (20.5%) of well differentiated adenocarcinoma. Moderately differentiated adenocarcinoma included 25 cases (56.8%) and poorly differentiated adenocarcinoma constitute 10(22.7%) cases. 6/9 (66.7%) of well differentiated adenocarcinoma, 11/25(44%) of moderately differentiated adenocarcinomas and 4/10(40%) of poorly differentiated adenocarcinomas showed positivity for AMACR expression. Although there was increase in AMACR expression with relation to increase in histological differentiation, it was not statistically significant (p value-0.43). AMACR expression in Dysplasia and Carcinoma is statistically significant than expression in gastritis with a P- value of 0.006. Odd’s ratio reveals that positive expression of AMACR is 11 times associated with carcinoma / dysplasia rather than gastritis. CONCLUSION: AMACR can be considered as one such candidate for targeted therapy as its expression is significantly higher in neoplastic tissue compared to non-neoplastic tissue of stomach. IHC for AMACR can be used for differentiating the cases of reactive atypia from early neoplastic lesions which will help in early identification.

Item Type: Thesis (Masters)
Additional Information: 201713051
Uncontrolled Keywords: Gastric adenocarcinoma, AMACR, Immunohistochemical evaluation, intestinal type gastric adenocarcinoma, diffuse type gastric adenocarcinoma.
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 29 Jan 2021 16:05
Last Modified: 29 Jan 2021 16:05

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