Oral Cavity Cancers Differentially Located in Non-Smokers, Smokers

Lateral tongue cancers are more common in non-smokers than in smokers

medwireNews: The location of oral cavity squamous cell carcinomas (SCCs) varies between non-smokers and smokers, with non-smokers more likely to develop tumours on the edge of the tongue, a retrospective study finds.

Christopher Perry, from Watkins Medical Centre in Brisbane, Queensland, Australia, and colleagues noted a difference between smokers and non-smokers with respect to the site of origin of oral cavity SCCs. Tumours on the edge of the tongue were significantly more frequent in non-smokers (65.5% of 87) compared with current or former smokers (35.3% of 303).

The site of SCCs was more evenly spread among current and former smokers, including 107 cases in the lateral tongue, 82 on the floor of the mouth, 38 in the retromolar trigone.

Additionally, when patients were stratified by gender, non-smoking women had a significantly higher incidence of oral cavity cancers than non-smoking men, with 53 of the 87 patients with oral cavity SCCs being female.

Complete data on the state of dentition was not available for all included patients, but Christopher Perry and co-workers point out that the medical records of 18 of the 57 non-smokers who had lateral tongue tumours contained notes on dental abnormalities resulting in ulceration or irritation. The authors hypothesise that chronic dental or denture irritation could explain the high incidence of tumours on the edge of the tongue noted in their study.

“This irritant effect may explain why lifelong non-smokers, in the absence of other major risk factors, develop oral cavity cancers most commonly on the lateral edge of their tongue”, the team writes in JAMA Otolaryngology-Head & Neck Surgery.

The average age of non-smoking patients with lateral tongue cancer was 61.8 years, whereas that of patients with gingival and floor of mouth tumours was 75.4 and 67.5 years, respectively. The authors point out that the gingiva and floor of mouth are key sites of trauma from chronic denture rubbing whereas younger individuals are more likely to have their own teeth.

They conclude: “We argue for an increasing recognition of the potential carcinogenicity of dental trauma in its own right and its cocarcinogenicity with smoking.

“Therefore, patients presenting to medical and dental services with evidence of dental irritation or premalignant changes to oral mucosa should have appropriate dental care to help prevent cancer development.”

Reference

Perry BJ, Zammit AP, Lewandowski AW, et al. Sites of Origin of Oral Cavity Cancer in Nonsmokers vs Smokers: Possible Evidence of Dental Trauma Carcinogenesis and Its Importance Compared With Human Papillomavirus. JAMA Otolaryngol Head Neck Surg 2014; Online first 6 November. doi:10.1001/jamaoto.2014.2620

medwireNews (www.medwireNews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014