Which of the following statements are True or False? 1. Genetic polymorphisms of the P450 enzyme system, specifically CYP1A1, or chromosome fragility are associated with the development of lung cancer. 2. Cigarette smoking increases the risk of squamous and small cell lung cancer cell types only. 3. Varenicline-nicotinic acetylcholine receptor paial agonist is used for nicotine dependence. 4. Low-dose, noncontrast, thin-slice helical or spiral chest CT has emerged as a possible new tool for lung cancer screening. 5. Extrathoracic metastatic disease is found at autopsy in 20% of patients with squamous carcinoma.