p53 expression but not p16(INK4A) correlates with human papillomavirus-associated esophageal squamous cell carcinoma in Kazakh population.

BACKGROUND

p16(INK4A) expression has been used as a surrogate marker for human papillomavirus (HPV) infection in cervical cancer and head and neck cancer. p53 has also been reported as a feasible marker to identify HPV-positive oropharyngeal carcinoma and penile lesions. This study aimed to investigate p16(INK4A) and p53 expression levels and their correlation with HPV status and clinical parameters in Kazakh patients with esophageal squamous cell carcinoma.

METHODS

Immunohistochemical expression of p16 (INK4A) and p53 were evaluated in 163 cases of esophageal squamous cell carcinoma in Kazakh patients. The presence of HPV DNA was detected by polymerase chain reaction.

RESULTS

p16 (INK4A) -positive expression was detected in 19.0 % of patients, and its expression was significantly correlated with a lower frequency of lymph node metastasis (p = 0.038). By contrast no significant association was found between p16 (INK4A) -positive expression and HPV status (correlation coefficient = -0.062, p = 0.499). p16 (INK4A) -positive expression did not affect the odds of tumors being HPV positive (odds ratio [OR] = 0.727 with 95 % confidence interval [CI] = 0.288-1.836). The sensitivity of p16 (INK4A) -positive expression as an HPV marker was 0.164, with a specificity of 0.788 and a positive predictive value of 0.391. p53-positive expression was present in 88.3 % of all cases. Although no significant correlation with available clinical parameters was found, a significantly inverse correlation was observed between p53 expression and HPV status (correlation coefficient = -0.186, p = 0.039). Moreover, p53-positive expression decreased the odds of tumors being HPV positive (OR = 0.292 with 95 % CI = 0.086-0.990). The sensitivity of p53-negative expression as an HPV marker was 0.179, with a specificity of 0.940 and a positive predictive value of 0.714. The overall HPV prevalence was high (45.5 %) in Kazakh patients, with no significant association between HPV positivity and available clinical parameters or combined p16 (INK4A) /p53 expression.

CONCLUSIONS

p16 (INK4A) -positive expression was associated with lymph node metastasis. Results indicate that p53-negative expression and not p16 (INK4A) -positive expression may be used as a marker for HPV status in ESCC; however, this finding requires further studies for validation.