Drug resistance analysis of gefitinib-targeted therapy in non-small cell lung cancer

The aim of the study was to examine the drug resistance analysis of gefitinib-targeted therapy in non-small cell lung cancer (NSCLC). In total, 156 NSCLC patients without surgical treatment were selected, including 117 cases of adenocarcinoma (75%), to receive single gefitinib 0.25 g/day or combined with platinum chemotherapy. Computed tomography was used to evaluate tumor growth for the response and non-response groups. The chemotherapy regimen was changed or combined with radiotherapy in the non-response group. Tumor progression or metastasis in the response group was considered as the generation of drug resistance. The chemotherapy regimen was altered in the response group. Eleven cases had tumor response in the non-response group after the chemotherapy regimen was adjusted (20%), 33 cases had complete response (CR) (32.7%), 44 cases had partial response (PR) (43.6%), and 24 cases had stable disease (SD) (23.8%) in the response group. The drug resistance rates of CR, PR, and SD showed no significant difference (P>0.05). However, the drug-resistant time of CR was significantly delayed and the difference was statistically significant (P<0.05). The response rates of CR, PR, and SD patients regaining the response rate showed no statistical significance after the chemotherapy regimen was adjusted, and the difference was not statistically significant (P>0.05). In conclusion, gefitinib-targeted therapy in NSCLC showed certain drug resistance, which may not be related to the response.