Patients with more dental caries (cavities) are less likely to be diagnosed with head and neck squamous cell carcinoma (HNSCC) than patients with fewer or no cavities, according to a study published Online First by JAMA Otolaryngology–Head & Neck Surgery.
Tooth decay happens when teeth are demineralized by lactic acid produced from the fermentation of carbohydrates by bacteria. The bacteria that cause tooth decay are associated with an immune response shown in some studies to be protective against cancer, according to the study background.
The study by Mine Tezal, of the University at Buffalo, the State University of New York, and colleagues was conducted at a comprehensive cancer center and included all patients with newly diagnosed HNSCC between 1999 and 2007. The study included 399 patients with cancer and 221 control participants without a cancer diagnosis.
Of the 399 patients with HNSCC, 146 (36.6 percent) had oral cavity squamous cell carcinoma (SCC), 151 (37.8 percent) had oropharyngeal SCC and 102 (25.6 percent) had laryngeal SCC. Patients with cavity numbers in the upper third of the study population were less likely to have HNSCC than those patients in the lower thirds, according to the results.
“Caries is a dental plaque-related disease. Lactic acid bacteria cause demineralization (caries) only when they are in dental plaque in immediate contact with the tooth surface. The presence of these otherwise beneficial bacteria in saliva or on mucosal surfaces may protect the host against chronic inflammatory diseases and HNSCC. We could think of dental caries as a form of collateral damage and develop strategies to reduce its risk while preserving the beneficial effects of the lactic acid bacteria,” the study concludes.
(JAMA Otolaryngol Head Neck Surg. Published online September 12, 2013. doi:10.1001/jamaoto.2013.4569.