Disclosed is a method of treating a subject having non-small cell lung cancer. The method includes administering to the subject a therapeutically effective amount of a composition and the composition contains 5-demethylnobiletin and docetaxel. Compared with the use of docetaxel alone, the method of combining 5-demethylnobiletin and docetaxel had a 4.4 fold increase in inhibiting the growth of human lung cancer cells, and had a 3.05 fold increase in inhibiting tumor growth in human lung cancer cell-engrafted nude mice.
