Risk Factors of Head-and-neck Squamous Cell Carcinoma: Beyond Tobacco

The article by Michaelraj et al. on the risk factors of head-and-neck cancer in southern India further reinforced the fact that tobacco is the most prevalent cause of oral cancer throughout the country.[1] Social awareness against the consumption of tobacco remains the key to controlling the rising number of patients with cancer.[2] The study also showed that about 24% of men and 38% of women had no history of tobacco or alcohol use. Furthermore, 42.5% of the patients were in the age group 31–50 years and did not have a history of substance abuse. Various etiological factors for head-and-neck cancer besides tobacco and alcohol have been described in an article by Perdomo et al.[3] It would have been helpful if the questionnaire used for the study had included other risk factors like oral hygiene, nutrition, occupational hazards, and environmental details which would have helped gain more insights into the causes of the cancers that were not attributable to tobacco or alcohol. Though oropharyngeal cancer is commonly associated with human papillomavirus (HPV) infection, the International Agency for Research of Cancer (IARC) in 2012 declared that there was sufficient evidence to associate a subtype of HPV with oral and laryngeal cancers.[4] Multiple studies across India have reported heterogeneity in the prevalence of HPV in head-and-neck cancers, ranging from 0 to 86.6%.[5] The authors of the present study[1] could have collected data on HPV infection from oral and laryngeal cancers in addition to the patients with oropharyngeal cancer. Various epidemiological studies have suggested that tobacco use and HPV infection are mutually exclusive risk factors for head-and-neck cancer, while others have shown a synergistic effect.[6,7] Details regarding the presence of HPV infection in the users and non-users of tobacco in the study by Michaelraj et al.[1] could have provided important data on the relationship between tobacco use, HPV infection, and head-and-neck cancer. Another significant finding of the study by Michaelraj et al.[1] was the relatively high prevalence of hypopharyngeal cancer, which was the second most common site involved in 18.7% of the patients. Furthermore, 40% of patients with hypopharyngeal cancer had no history of tobacco or alcohol use.[1] Nutritional factors and exposure to other pollutants could be investigated in these patients, as hypopharyngeal cancers usually have a poor prognosis. To conclude, I agree with the authors that middle-aged males are most commonly affected by head-and-neck cancers, and spreading awareness against tobacco and alcohol use is important. Further profiling of risk factors in non-tobacco users and female patients will help to close the gaps in the etiological landscape of head-and-neck cancer. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.