Many publications have shown that the development of resistance in patients with non-small cell lung cancer (NSCLC) with a mutation in the EGFR gene to targeted treatment with tyrosine kinase inhibitors (TKIs) inevitably occurs after an average of 12 months. Therefore, the use of preoperative targeted treatment for this period or more may lead to the development of resistance at surgery. In locally advanced and disseminated NSCLC, this may adversely affect the results of postoperative targeted therapy with first- and second generation TKIs and, as a result, worsen overall treatment outcomes.

OBJECTIVE

To compare the results of therapy in patients who received targeted treatment for 9 months (before the expected emergence of the T790M resistance mutation) and longer.

MATERIAL AND METHODS

For retrospective analysis, the investigators identified a group of 40 patients with stage III—IV NSCLC, who received targeted EGFR TKI therapy + surgical removal of the primary lesion. The follow-up and treatment periods were 10 years since 2010. All the patients were diagnosed with primary lung adenocarcinoma with EGFR mutations: deletions in exon 19 (Del19), L858R in exon 21, or T790M in exon 20. The patients received targeted therapy with first-, second-, or third- generation TKIs. These included 5 (12.5%) men and 35 (87.5%) women; their mean age was 58.5 years (range 39 to 80 years).

RESULTS

Comparison the patients who received preoperative therapy for 9 months revealed a significant and statistically significant improvement in overall and disease-free survival. The patients who received preoperative targeted therapy for 9 months did not achieved the median relapse-free and overall survival, while those who received targeted preoperative therapy for more than 9 months had median relapse-free and overall survivals of 31 and 44 months, respectively.

CONCLUSION

The results of the retrospective analysis suggest that a shorter (no more than 9 months) targeted preoperative treatment in patients with Stage III and IV NSCLC in the presence of mutations in the EGFR gene causes an improvement in survival rates.