Correlation of HPV16 infection and p16 expression with prognosis in patients with hypopharyngeal carcinoma

The aim of this study was to explore the relationship between HPV16 infection, p16 protein expression and prognosis in patients with hypopharyngeal carcinoma. Totally 46 cases of hypopharyngeal carcinoma specimens were selected from January 1, 2004 to December 31, 2011 in Tangshan Union Hospital. PCR-reverse dot blot hybridization was used to detect infection of HPV16, and SP immunohistochemical method was adopted to detect the expression of p16 protein in hypopharyngeal carcinoma tissues. Clinical data were collected and all the patients were followed up. Results showed that the infection rate of HPV16 in hypopharyngeal carcinoma tissues was 26.1% (12/46). No significant difference was found between HPV16 infection and patients’ age, gender, primary tumor site, histological differentiation and TNM classification (P > 0.05). The expression rate of p16 protein in hypopharyngeal carcinoma tissues was 39.1% (18/46). Expression of p16 proteins was not significantly correlated with patients’ age, gender, primary tumor site, histological differentiation and TNM classification (P > 0.05). However, HPV16 infection was positively correlated with the p16 expression in hypopharyngeal carcinoma tissues, with a correlation coefficient of 0.437 (P = 0.002). Kaplan-Meier analysis showed that HPV16-positive patients had a higher median overall survival than HPV16-negative ones (75 months vs. 51 months, respectively. P = 0.001). Median progression-free survival was virtually the same for both HPV16-positive and HPV16-negative patients (77 months vs. 49 months, respectively. P = 0.002). P16-positive patients had a higher median overall survival than p16-negative ones (69 months vs. 53 months, respectively. P = 0.001). Median progression-free survival was also almost the same for both p16-positive and p16-negative patients (68 months vs. 43 months, respectively. P = 0.003). In conclusion, there is a positive correlation between HPV16 infection and positive expression of p16 protein in hypopharyngeal carcinoma. Patients with HPV16 infection might have favorable prognosis compared with HPV16negative ones. P16 positive expression predicates a better prognosis in patients with hypopharyngeal carcinoma.