Reformed smokers have survival benefits after head and neck cancer

Smoking tobacco is the main risk factor for head and neck cancer, is proportional to the number of pack years (number of packs smoked/day x number of years of smoking), and is reduced when the patient stops smoking. Current molecular evidence has suggested that tobacco-related cancers could be clinically more aggressive than cancers in non-smokers, particularly in the head and neck. However, clinical studies have not uniformly reproduced the relation between survival and tobacco, possibly because they ignore the health benefit that reformed smokers obtain during the period between giving up smoking and the diagnosis of cancer, which is not shared by those who continue to smoke and develop cancer. We have investigated the survival of reformed smokers, non-smokers, and continuing smokers after a diagnosis of head and neck cancer. The data of patients with head and neck cancer from 1992 -2013 from the Cancer Genome Atlas database were analysed using a multivariate Cox's regression model for survival, and Kaplan-Meier curves were produced for smoking history. A total of 521 patients were treated for head and neck cancer, and there was a significant difference in survival between reformed and non-smokers on the one hand, and current smokers on the other (p = 0.02). The significance increased when reformed smokers were grouped according to their duration of abstinence and time of diagnosis of cancer (>15 and ≤15 years, p < 0.01). Smoking history was a significant prognostic factor in the multivariate Cox's regression model when analysed with age, stage, grade, and site. We conclude that reformed smokers have a survival benefit in head and neck cancer.