Clinicopathologic significance of serum response factor expression in colorectal adenocarcinomas

Abstract

Background and aim: The purpose of this study was to investigate the role of serum response factor (SRF) expression and to evaluate its correlation with various clinicopathological parameters in colorectal adenocarcinomas. Methods: We used tissue microarrays consisting of 24 normal mucosa, 50 tubular adenomas, 496 adenocarcinomas, and 128 metastatic lesions. Results: The expression of SRF was rare in normal colonic mucosa with a mean expression score of 0.67 ± 0.17. Tubular adenomas had a mean expression score of 2.48 ± 0.31, adenocarcinomas 2.82 ± 0.13 and lymph node metastases 2.82 ± 0.36. Interestingly, SRF expression was high in distant metastases with a mean expression score of 4.83 ± 0.43. The mean SRF expression was increased significantly early in the normal‐adenoma‐carcinoma sequence and again in distant metastases. The positive SRF expression was strongly correlated with non‐mucinous tumor type (P < 0.001). Moderately and poorly differentiated adenocarcinomas had higher mean expression scores than well‐differentiated adenocarcinomas (2.88 ± 0.13 vs 1.33 ± 0.32) (P= 0.015). There were significant associations between SRF expression and expression of p53 (P= 0.034) and Ki‐67 (P= 0.001). Conclusions: Our results suggest that SRF expression may be the early event of normal‐adenoma‐carcinoma sequence of colorectal cancer, especially in adenomatous change of colonic mucosa and may play an important role in distant metastasis of colorectal cancers.