Squamous Cell Carcinoma of the Oral Cavity in Ever Smokers: A Matched-Pair Analysis of Survival

Smoking is associated with oral cancer, and to adopt a more healthy lifestyle, increasing numbers of people are choosing to give up the habit. However, the occurrence of oral cancer in ever smokers is still apparent. In this study, we investigated the survival of ever smokers with oral squamous cell carcinoma compared with nonsmokers and current smokers with oral squamous cell carcinoma. A matched-pair study was performed between 2005 and 2012, which matched 66 ever smoker patients with oral cancer to both current smokers and never smokers: each ever smoker was matched with 1 never smoker and 1 current smoker. A Chi-squared test was used to evaluate the significance of the variables, and the Kaplan-Meier method was used to analyze the recurrence-free survival and disease-specific survival rates. The recurrence-free survival (P = 0.006) and disease-specific survival (P = 0.027) rates were worse for ever smokers compared with never smokers, but the former group shared a similar prognosis with current smokers. The matched-pair analysis showed that smoking was associated with an approximately 2-fold increase in the risk for recurrence and 5-fold increase in risk for disease-related death. Ever smokers and current smokers had a similar chance of recurrence and disease-related death, but ever smokers had a poorer prognosis than never smokers do and they tended to have a local recurrence. The recurrence-free survival and disease-specific survival rates did not differ between ever and current smokers, and smoking cessation did not affect the chance of recurrence and diseases-related death in ever smokers compared with current smokers.