Clinicopathological association of p16 and its impact on outcome of chemoradiation in head-and-neck squamous cell cancer patients in North-East India

Abstract

Purpose: Human papillomavirus-associated head–and-neck squamous cell cancer (HNSCC) is following an increasing trend in Western countries, which has unique biology and confers better prognosis, whereas there are limited data from Indian studies in this context. Methods: We conducted a prospective cohort study to evaluate the clinicopathological association of p16 in locally advanced HNSCC and its impact on outcome of chemoradiation. The study population was divided into two arms; p16-positive and p16-negative arms. All patients were treated with concurrent chemoradiation using weekly cisplatin. Statistical Analysis Used: SPSS version 21 for Windows was used for statistical analysis. Chi-square test and multivariate analysis were performed to evaluate different association and impact of p16. P <0.05 was considered statistically significant. Results: The present study found p16-positive HNSCC patients to be associated with better performance status (P = 0.010), oropharyngeal primary location (P = 0.034), advanced nodal stage at presentation (P = 0.000), and higher histopathologic grade of tumor (P = 0.021) and was associated with better response (P = 0.005) to concurrent chemoradiation. Subsite analysis revealed p16-positive oropharyngeal squamous cell cancer (OPSCC) to have significantly better response (P = 0.036) to chemoradiation, whereas a trend toward better response to chemoradiation (P = 0.066) was found among p16-positive non-OPSCC. Higher p16 expression score was associated with better (P = 0.000) response to chemoradiation. Multivariate analysis revealed p16 to have an independent positive impact on tumor response to chemoradiation in HNSCC irrespective of tumor subsite. Conclusion: p16 overexpression is a good prognostic factor in both OPSCC and non-OPSCC. Treatment response have a positive correlation with intensity of p16 staining in the tissue biopsy material.