Evaluation of oral cancer trends in Pakistan during the period 2010 to 2016

Abstract

Background: Head and neck squamous cell carcinoma is the commonest cancer in Sri Lanka representing 24% of all male cancers. Traditionally risk factors included smoking and betel chewing, however HPV is now considered an important causative agent for oral cancers.HPV association in oral cancers has not been studied in Sri Lanka. This study investigates the HPV association in Sri Lankan patients with oral cavity and oropharyngeal cancers. Methods: We conducted a cross-sectional study with three years of follow-up data. Eligible patients had oral cavity or oropharyngeal squamous cell carcinomas and were treated with chemoradiotherapy at the National Cancer Institute, Sri Lanka between April 2012 and March 2013. Real time PCR was performed on peripheral blood for the detection of HPV DNA prior to the chemoradiotherapy. Results: 69 patients were eligible with a mean age of 56.5 years, 94.2% were males. Overall, 47.8% patients were positive for HPV. 30% of HPV positive patients gave a history of smoking or betel chewing, whereas 50% of HPV negative patients were either smokers or betel chewers.72.5% patients had an oropharyngeal cancer with 46% were HPV positive. There was no association between HPV status with site of the primary lesion, TNM stage or the histological grade. In the HPV positive patients, 48.4% were HPV 18 positive and 27.3% were HPV 16 positive and 24.3% were both HPV 16 and 18 positive. In HPV negative compared to HPV positive patients, there was no significant difference in median overall survival at 8 months and 17 months respectively (p ¼ 0.41). HPV 16 and 18 co-infected patients had numerically higher median overall survival than either HPV 16 or HPV 18 mono-infected patients which were 17, 14, 12 months respectively (p ¼ 0.17). Conclusions: In our cohort, almost half of patients with oral cavity and oropharyngeal cancers were positive for HPV, with HPV 18 mono-infection most common.HPV positive patients had a numerically better median survival compared to HPV negative patients, although it did not reach statistical significance, potentially due to the small sample size. Further studies to confirm whether HPV status may be a good prognostic marker are warranted.