The increasing incidence of lung cancer in Lithuania and in the world remains relevant to improving the effectiveness of treatment. Lung cancer is often diagnosed at an older age. Non-small cell lung cancer accounts for about 85%, and small cell lung cancer 15% of all diagnosed lung cancers. About 25% of newly diagnosed non-small cell lung cancer cases are stage I and II, in other cases, however, local or distant spread of lung cancer is detected, when surgical treatment is not indicated. Early-stage non-small cell lung cancer treatment start is radical resection, if the patient’s condition allows. After the operation, an adjuvant platinum–based chemotherapy is combined with etoposide. We analyzed 82 IB–IIIA non-small cell stage lung cancer sufferers who underwent radical resection in combination with a subsequent adjuvant chemotherapy. 1–2 of years after surgery disease progression was noted in 22 patients (27%), while in the 60 (73%) we observed disease remission. These findings stress necessity of additional DNA testing to individualize the treatment itself and improve treatment outcome.