Impact of Smoking on Treatment Outcome of the Glottis Laryngeal Cancer

Objective. To investigate the effect of age and smoking on the treatment outcome of the glottis laryngeal cancer. Background. The incidence of laryngeal tumors is closely correlated with smoking. Death from laryngeal cancer is 20 times more likely for the heaviest smokers than for nonsmokers. Methods. A total of 1745 individuals with glottis squamous cell carcinoma diagnosed between January 1st of 1995 and December 31st in 2002 were studied in this research. We used the relative risk as the measure of association of treatment (surgery vs radiotherapy) and vital status (dead or alive). We considered factors such as ethnicity, histology, stage and age groups (young vs elder) and the behavior of smoking. We used the Mantel-Haenszel stratified analysis to determine if each of the above is a confounder, effect modifier, or just a risk factor. Results. Age group was found to be a confounder, while stage was an effect modifier for the treatment-outcome association. Smoking was found to be a risk factor, as well as the squamous cell carcinomas. The elderly (\u3e60 years old), smoker patients who undergo radiotherapy alone are 46% more likely to die than those who undergo surgery alone, among those with localized glottis and squamous cell carcinomas of the larynx. Conclusions. Further research need to be done in order to fully explore what other factors may confound or modify the main association. Unfortunately, the cancer registry data has limited information, poorer than the hospital discharge data. The importance of this study resides in a reliable finding about the elderly smokers that should follow a surgery treatment that is less risky than radiotherapy. Grants and Acknowledgement. This study was funded in part through the HPD Research Grant for Florida Cancer Registry Analysis, 2004-2007. The views expressed herein are solely those of the authors and do not necessarily reflect those of FCDS, the contractor of FL-DOH