The clinical significances of the abnormal expressions of Piwil1 and Piwil2 in colonic adenoma and adenocarcinoma

OBJECTIVE: The objective of the present investigation was to study the clinical significances of the abnormal expressions of Piwil1 and Piwil2 protein in colonic adenoma and adenocarcinoma. METHODS: This study had applied immunohistochemical method to detect 45 cases of tissues adjacent to carcinoma (distance to cancerous tissue was above 5 cm), 41 cases of colonic adenoma and 92 cases of colon cancer tissues, and their Piwil1 and Piwil2 protein expression levels. ANALYSIS: The correlation of both expression and its relationship with clinicopathological features of colon cancer was analyzed. RESULTS: Positive expression rates of Piwil1 in tissues adjacent to carcinoma, colonic adenoma, and colon cancer were 11.1% (5/45), 53.7% (22/41), and 80.4% (74/92), respectively; the expression rates increased, and the comparisons between each two groups were statistically significant (P<0.05). In each group, the positive expression rates of Piwil2 were 24.4% (11/45 cases), 75.6% (31/41 cases), and 92.4% (85/92 cases); expression rates increased, and the comparisons between each two groups were statistically significant (P<0.05). Piwil1 expression and the correlation of the degree of differentiation, TNM stage, and lymph node metastasis were statistically significant (P<0.05). Piwil2 expression and the correlation of the degree of differentiation, tumor node metastasis (TNM) stage, and lymph node metastasis had no statistical significance (P>0.05). In colon cancer tissue, Piwil1 and Piwil2 expressions were positively correlated (r=0.262, P<0.05). CONCLUSION: The results showed that the abnormal expression of Piwil1 and Piwil2 might play an important role in the process of colon cancer development.