Background:
Tobacco smoking (TS) remains the most established cause of lung carcinogenesis and other disease processes. In Kazakhstan lung cancer (LC) occupies by far the first position in the cancer mortality structure. Identification of the morphological and immunohistochemical features of tumors among smokers may enable individualized treatment and reduce mortality.

Methods:
Morphological, histological, molecular genetics, immunohistochemical methods were used. The slides of 286 patients (204 smokers and 82 nonsmokers) with LC were studied. For molecular genetic studies tumor blocks of 47 patients (27 smokers and 20 nonsmokers) were used.

Results:
There are differences in the histotype structure of LC among smokers and nonsmokers. Squamous cell carcinoma prevails among men as adenocarcinoma among women. It was found that smokers had squamous cell carcinoma histotype predominant, which share above 1.4 times (p < 0.01), and small cell carcinoma 2.0 times (p < 0.05). Adenocarcinoma is 3.5 times (p < 0.001) more likely to develop in the group of non-smokers. Activating of epidermal growth factor receptor mutations were detected in 21.3% of the patients with non-small cell LC. Mutations occur most often among women (70%) than among men (30%) and most among non-smokers than among smokers (90% and 10% respectively). Immunohistochemical studies of LC tumor have shown that smokers have a higher proliferative activity of tumor cells, indicating the adverse effects of smoking for the LC prognosis.

Conclusions:
The data obtained allow to individualize the postoperative radiation therapy and adjuvant chemotherapy to improve the efficiency of LC treatment. Considering that the presence of the mutations associated with the possibility of targeted therapy, LC treatment prognosis in smokers less favorable than that of nonsmokers. Advising the patient to quit by clinicians is an important preventive technology for prevention of LC morbidity and premature mortality.