Prognostic value of human papillomavirus infection and p53, p16, epidermal growth factor receptor and p34cdc2 expression in patients with salivary adenoid cystic carcinoma.

The aim of this study was to explore the correlation between HPV infection, p53, p16, epidermal growth factor receptor (EGFR), p34cdc2 protein expression and prognosis in patients with adenoid cystic carcinoma of salivary gland. Totally 78 cases of adenoid cystic carcinoma of salivary gland specimens were selected from January 1, 2004 to December 31, 2013 in Tangshan Union Hospital. PCR-reverse dot blot hybridization was used to detect infection of human papilloma virus (HPV), and SP immunohistochemical method was adopted to detect the expression of p53, p16, EGFR and p34cdc2 protein in the carcinoma tissues. Clinical data were collected and the patients were followed up. Results showed that the infection rate of HPV in adenoid cystic carcinoma tissues was 0% (0/78). The expression rate of p53, p16, EGFR and p34cdc2 protein in carcinoma tissues were 75.6% (59/78), 57.7% (45/78), 60.1% (47/78) and 64.1% (50/78), respectively. Expression of p53, p16, EGFR and p34cdc2 proteins was not significantly correlated with patients' age, gender, disease location, TNM classification and histological type (P > 0.05). Kaplan-Meier analysis showed that EGFR-positive patients had a lower median overall survival than EGFR-negative ones (58 months vs. 75 months, respectively. P = 0.001). The result of median progression-free survival was virtually the same for both EGFR-positive and EGFR-negative patients (43 months vs. 49 months, respectively. P = 0.002). p34cdc2-positive patients had a lower median overall survival than p34cdc2-negative ones (61 months vs. 71 months, respectively. P = 0.027). Median progression-free survival was also almost the same for both p34cdc2-positive and p34cdc2-negative patients (44 months vs. 51 months, respectively. P = 0.011). Cox regression analysis showed that expression of EGFR and p34cdc2 was independent risk factors for the prognosis of patients with adenoid cystic carcinoma of salivary gland (relative risk = 13.199, 11.466, P < 0.001). In conclusion, HPV infection is not detected in salivary adenoid cystic carcinoma tissues. p53, p16, EGFR and p34cdc2 protein are positively expressed in most salivary adenoid cystic carcinoma tissues. p16 is unsuitable as a surrogate for HPV infection status in patients with adenoid cystic carcinoma of salivary gland. Expression of EGFR and p34cdc2 is independent risk factors in the prognosis of patients with salivary gland adenoid cystic carcinoma. Patients with EGFR or p34cdc2 positive expression should be followed up closely. IJCEP