Role of Hepatocyte Paraffin 1 antigen in the course of colorectal carcinogenesis.

BACKGROUND Few studies have reported the expression of Hepatocyte Paraffin 1 (Hep Par 1) in colorectal carcinomas with contradictory results. Reported rate of expression ranged from 4-50%. Moreover, the correlation between Hep Par 1 expression and clinicopathological parameters has not been investigated. The objective of the present study was to investigate the role of CPS1 (using Hep Par 1) in colonic carcinogenesis and characterize carcinomas which express it. MATERIAL AND METHOD Comparative analysis was done between Hep Par 1 expression in normal colonic mucosa (n=10), adenomatous polyps (n=29) and sporadic adenocarcinoma (n=40) and was correlated with clinicopathologic parameters. RESULTS Normal colonic mucosa did not express Hep Par 1. In contrast, it was expressed in dysplastic glands and neoplastic cells of well-moderately differentiated non-mucinous adenocarcinomas. Hep Par 1 was found in 47.5% of colonic carcinomas, 41.7% of polyps with high grade dysplasia (HGD) and 23.5% of polyps with low grade dysplasia (LGD). Mean Hep Par-1 score, likewise, was highest in carcinoma, high in polyps with HGD and lowest in polyps with LGD. Hep Par 1 expression inversely correlated with some conventional prognostic parameters including tumour type, grade, lymph node metastasis and AJCC stage. It did not correlate with depth of invasion or lymphovascular invasion. CONCLUSION Hep Par 1 (i.e. CPS1) might play an active role in initiation of dysplasia and progression of multistep colorectal carcinogenesis. However, it seems that CPS1 is not involved in invasion and tumour spread. Conversely, it might be in the play of suppressing cancer progression. These findings could have both prognostic and therapeutic applications.