Final answer:
The most likely contributing factor for the development of lung cancer in this patient is cigarette smoking.
Step-by-step explanation:
The most likely contributing factor for the development of lung cancer in this patient is cigarette smoking.
Smoking is the major cause of lung cancer, accounting for about 85 percent of cases. Cigarette smoke contains numerous cancer-causing chemicals, and smoking causes 90 percent of lung cancers. When tobacco smoking is combined with other risk factors such as exposure to radon or asbestos, the risk of lung cancer is heightened.