Tumor response to radiotherapy and expression of epidermal growth factor receptor mutation and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase rearrangement in patients with non-small cell lung cancer.

BACKGROUND: One of the main limitations of radiation therapy is the resistance of tumor cells. This study aimed at evaluating the relationship between the expression of epidermal growth factor receptor (EGFR) and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) and tumor radiosensitivity in patients with non-small cell lung cancer. METHODS: Medical case files, pathological results for EGFR and EML4-ALK, and computerized tomography scans of patients with NSCLC treated with thoracic radiation therapy were analyzed. RESULTS: The sample size was 101 patients with mean age 58.43 ± 9.89 years. Statistically significant differences were observed in the mean reduction of long tumor diameter during the early treatment phase in EGFR-positive versus EGFR-negative patients (p value = 0.04) and in short tumor diameter during the late treatment phase in EGFR-positive versus EGFR-negative patients (p value = 0.04). CONCLUSION: Patients with overexpression of EGFR mutations are more radiosensitive during the early treatment phase, and EML4-ALK mutations were less radiosensitive regardless of phases.