Teeth loss and risk of cancer at 14 common sites in Japanese.

BACKGROUND Tooth loss has been associated with a higher risk of several types of cancer. To clarify the significance of tooth loss to the risk of 14 common cancers, we conducted a large-scale, case-control study based on the Hospital-based Epidemiologic Research Program at Aichi Cancer Center. METHODS A total of 5,240 cancer subjects and 10,480 age- and sex-matched noncancer controls were recruited. Patients with 14 types of cancer newly diagnosed from 2000 to 2005 were eligible as case subjects, and new outpatients without cancer in the same time period were eligible as controls. Tooth loss was categorized into four groups: group 1, number of remaining teeth, >or=21; group 2, 9 to 20; group 3, 1 to 8; and group 4, 0. The effect of tooth loss was assessed as odds ratios (OR) with 95% confidence intervals (95% CI) calculated with conditional logistic regression models, with adjustment for potential confounders. RESULTS A decreased number of remaining teeth was associated with increased OR of head and neck (OR, 1.68; 95% CI, 0.88-1.93; P trend = 0.055), esophageal (OR, 2.36; 95% CI, 1.17-4.75; P trend = 0.002), and lung (OR, 1.54; 95% CI, 1.05-2.27; P trend = 0.027) cancers. CONCLUSIONS We showed a significant positive association between tooth loss and the risk of head and neck, esophageal, and lung cancers after adjustment for potential confounding factors. The findings indicate that preventive efforts aimed at the preservation of teeth may decrease the risk of these cancers.