Background/aims: Type 1 collagen is the most abundant protein in the human body and a major constituent of the interstitial connective tissue. However, little is known about carboxy-terminal propeptide of type I procollagen (PICP) expression in human colorectal tumor tissues. We therefore evaluated the concentrations of PICP in colorectal tumor tissue as well as surrounding normal tissues and examined the relationship between its level and clinicopathological variables.
Methodology: Tumor and normal tissues from 40 patients with colorectal carcinoma who had been operated on were stored at -80 degrees C until assays. PICP was assayed by sandwich immunoassay.
Results: It was found that the PICP level was significantly higher in the tumor extracts than in the normal tissue extracts (P < 0.0001). The ANOVA test showed that the level of PICP in tumor tissue was higher in the patients with advanced colorectal tumor than those with early stage disease (P < 0.0001). There were statistically significant differences with regard to the depth of tumor invasion, presence of lymph node metastasis, and hepatic metastasis (P < 0.05). There were also quantitative differences with respect to the PICP levels between obstructing tumors and non-obstructing carcinoma (P < 0.05), but the elevated PICP levels in tumor tissues were not associated with the type of histologic differentiation (P > 0.05).
Conclusions: Although these findings suggest that PICP value in tumor tissue is most likely related to the some histomorphological architecture of the tumor, the authors believe that the prognostic significance of PICP expression in primary colorectal tumor and normal tissues requires further evaluation.