Impact of Molecular Predictors on the Response Rates in Head and Neck Cancer Patients – an Observational Study

Abstract

Squamous cell carcinoma of head and neck region account for more than 25 % of male and more than 10 % of female cancers in India (1). Head and neck cancer treatment includes a multidisciplinary approach involving all specialties. Concurrent chemo-radiation is the standard of care in most of the subsites (2). Inspite of the multi-disciplinary approach, a plateau has been reached in terms of results with 5 year survival of locally advanced disease of around 30 % (3). In order to improve outcomes, there has been considerable interest in molecular profiling of head and neck cancers 4-10. However there is still significant paucity in terms of Indian data, hence the need for the study. The objectives are to assess the HPV-p16, EGFR and p53 status, to correlate HPV-p16, EGFR and p53 status with the response rates, to correlate HPV-p16,EGFR and p53 status with other factors like age, sex, tobacco use. Twenty five consecutive cases of histopathologically proven head and neck cancers were accrued. All patients were treated with external radiation to a dose of 66Gy in 33 fractions along with concurrent weekly cisplatin chemotherapy at a dose of 40mg/sqm. HPV-p16, EGFR and p53 mutation analysis was done on paraffin embedded histopathological blocks. PCR technique used for HPV-p16, EGFR and p53 status detection. Response assessment was done based on RECIST criteria. Correlation of HPV, EGFR and p53 status on response was done. The EGFR positivity rate was 84 %, the p53 positivity rate was 76 % and the HPV p-16 positivity rate was 28 %. Out of 25 patients, 13(52%) had complete response, 7(28 %) had partial response, 3(12 %) had stable disease and 2(8 %) had progressive disease. On correlation of molecular profile with response, there was no statistical significance between EGFR status and response (p 0.5) or HPV-p16 and response (p 0.8). However, p53 positivity was approaching significance with respect to good response (p 0.07).