Does AMACR and Cyclin D1 Immunohistochemical Expression Vary on Comparing Mismatch Repair Proficient Versus Deficient Colorectal Carcinomas?

Aim of Study: AMACR & Cyclin D1 expression in relation to different clinicopathological features was compared in MMR proficient versus deficient CRC subgroups.

Methodology: MLH1 & MSH2 immunostaining was used to sort studied carcinomas. AMACR, cyclin D1 & ki67 expression was evaluated in neoplastic & non-neoplastic lesions too.

Results: Of studied carcinomas, 40% were MMR proficient & 60% were MMR deficient. Low AMACR expression was detected in 50% & 66.7% of MMR proficient & deficient subgroups respectively. Cyclin D1 displayed high expression in 66.7% of MMR proficient & low expression in 53.3% of MMR deficient subgroups. AMACR is significantly related to gender, grade, extracellular mucin and dirty necrosis in MMR deficient while only to circumscription in MMR proficient subgroups. Cyclin D1 associated significantly with location, gross features, histologic type, pT, and pN in MMR proficient, and with location, histologic type, pT, pN, tumor stage, extracellular mucin, buds and dirty necrosis in MMR deficient subgroups. Correlations between AMACR and both cyclin D1 and Ki67 expression was significant in MMR deficient but were insignificant in MMR proficient subgroups. In both subgroups, the correlation between cyclin D1 and Ki67 expression was significant.

Conclusion: AMACR and cyclin D1 seem to have a role in CRC carcinogenesis & genomic status influences their expression.