Immunohistochemical expression of cyclin D1 in colorectal adenomas: a clinicopathological study

Background and objectives
The colorectum is the segment of the gastrointestinal tract most frequently affected by tumors. Most colonic tumors are benign epithelial polyps. There are many histologic types of polyps. The best characterized and most common cancer precursor is the adenomatous polyp. The size, number of adenomas, grade of dysplasia, and villous features predict the future risk for advanced neoplasia, including malignancy in patients who harbor adenomas. A number of studies have been published studies evaluating the clinical use of cyclin D1 immunohistochemical (IHC) expression as a predictor of malignant transformation in colorectal adenomas. The aim of the study was to evaluate the significance of IHC expression of cyclin D1 in colorectal adenomas as a marker for the prediction of malignant transformation.
Patients and methods
This study is a retrospective one in which a total of 39 formalin-fixed paraffin-embedded polypectomy specimens from patients with colorectal adenomas without concurrent or previous colorectal adenocarcinoma were retrieved from the archival materials during the period from March 2013 to March 2014. The histopathological diagnosis had been revised and all specimens were stained using IHC technique with cyclin D1.
Results
IHC expression of cyclin D1 had a significant correlation with villous type (=0.003) and high-grade dysplasia in adenomas (=0.021). However, there was no significant difference in the IHC expression of cyclin D1 according to the age and sex of the patients, and the size and site of colorectal adenomas (>0.05).
Conclusion
Cyclin D1 potentially contributes to the multistep process of colorectal oncogenesis. It plays an important role in the malignant conversion of colorectal adenomas, as it is more likely to be expressed in advanced adenoma with high-grade dysplasia and villous histology and can be used as an ancillary marker for the risk for malignant transformation and as a target for chemoprevention with anti-inflammatory drugs.