Cessation of Betel Quid Chewing, Smoking, and Alcohol Drinking and Risk of Oral Precancer and Oral Cancer.

Abstract

To quantify risk reduction in oral precancer and cancer with time since cessation of betel quid chewing, smoking, and alcohol drinking. We conducted a multicenter case-control study in Taiwan of patients with invasive oral cancer (n = 768), visual/clinical oral precancer (n = 1,998), and hospital-based controls (n = 717, recalibrated/reweighted to represent the Taiwan general population). Weighted logistic regression was used to evaluate associations of duration, intensity, and time since cessation of betel quid chewing without tobacco, smoking, and alcohol drinking (modeled using splines and categorically) with oral precancer and cancer risk versus controls. Risk of oral precancer increased with increased duration and intensity of chewing and smoking, and increased intensity of alcohol drinking. Risk of oral cancer increased with increased duration and intensity of chewing, increased duration of smoking, and increased intensity of alcohol drinking. For oral precancer, when compared with current users (defined as current users and individuals who quit for ≤2 years before study recruitment), odds ratios (ORs) for 10-year cessation of behaviors were as follows: chewing = 0.63 (bootstrap 95% CI, 0.43 to 0.83); smoking = 0.30 (95% CI, 0.18 to 0.41); and alcohol = 0.60 (95% CI, 0.34 to 0.86). Likewise, risk of oral cancer decreased with increasing time since cessation; ORs for 10-year cessation were as follows: chewing = 0.74 (95% CI, 0.44 to 1.05); smoking = 0.45 (95% CI, 0.22 to 0.67); and alcohol drinking = 0.55 (95% CI, 0.20 to 0.90). Adjusted population-attributable fractions show that cessation of chewing for ≥10 years would prevent an estimated 23.2% of oral precancers and 24.2% of oral cancers; cessation of smoking for ≥10 years would prevent 51.5% of oral precancers and 44.6% of cancers in Taiwan. Our findings support the potential for primary prevention of oral precancer and cancer through cessation of betel quid chewing (without tobacco), smoking, and alcohol drinking among current users.