Lung Cancer Treatment Influenced by Gender and Smoking

Objectives. 1. Is there an effect on treatment of lung cancer based on a patient’s gender? 2. Is there an effect on lung cancer patients who are undergoing treatments but fail to quit smoking? Background. Lung cancer is the leading cancer killer in all racial groups in the United States. It is responsible for approximately 3,000 lung cancer deaths annually. The prevalence of smoking in the United States is 28 percent for males and 25 percent for females, 18 years old or older age. Overall, the relative risk of developing lung cancer is increased about 13-fold by active smoking and 1.5-fold by long term passive exposure to cigarette smoke. Methods. Our analysis is based on the Florida cancer registry, similar to a cross-sectional study design, but selecting only incident cases, 88,994, between January 1st 1994 and December 31st 2002. We used the relative risk as a measure of association between treatment (surgery vs. radiotherapy) and outcome, vital status (dead vs alive). We analyzed two factors gender and smoking, and we defined exposure as treatment (surgery as “exposed” vs. radiotherapy as “unexposed”). The stratified Mantel-Haenszel methodology was used to assess confounders and/or effect modifiers. Results. Adjusting for localized stage and non-small cell histological type, females had a much higher risk of dying from radiotherapy alone than males, both smokers and nonsmokers. This is a cross-over effect of both found effect modifiers: tobacco and gender. Conclusion. Females are at higher risk at dying from lung cancer when undergoing radiotherapy alone, which perhaps is not the best treatment for lung cancer patients. Funding 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