P16INK4A overexpression predicts lymph node metastasis in cervical carcinomas

Background The p16(INK4A) protein (p16) is a cyclin-dependent kinase inhibitor that arrests the cell cycle in the G1 phase. Aim To explore the potential of p16 as a predictive marker for lymph node (LN) metastasis and prognosis in cervical carcinomas. Methods 145 patients diagnosed with FIGO stage I to IV cervical carcinoma were studied; 95 underwent LN dissection. The expression of p16 protein was studied by immunohistochemistry using tissue microarrays. Results Overexpression of p16 was seen in 108 of 145 (74.5%) invasive carcinomas. There was a significant correlation between p16 expression and LN metastasis (p=0.007). Patients with p16 overexpression had poorer survival than patients with p16 underexpression (59.3% vs 83.8% 5-year survival rate, log-rank p=0.015). In univariate analysis, p16 expression was a significant predictor of survival (RR 2.76, p=0.02). Conclusions Results suggest that p16 expression is an important predictive factor of LN metastasis in cervical cancer patients. Moreover, p16 overexpression is associated with a poor prognosis. Therefore, immunohistochemical evaluation of p16 expression is of potential value for treatment planning in cervical carcinomas.