Clinical value of alveolar lavage supernatant specimens in the detection of the EGFR gene mutation in patients with non-small cell lung carcinoma

BACKGROUND: This study sought to compare the consistency of the epidermal growth factor receptor (EGFR) gene mutation detection results in the supernatant of alveolar lavage specimens to the tissue sample results, and the consistency of the blood EGFR gene mutation detection results to the tissue detection results. METHODS: In total, 29 patients with non-small cell lung carcinoma (NSCLC) were selected, and their bronchoalveolar lavage fluid (BALF) was collected. The supernatant and precipitate were separated by centrifugation. Deoxyribonucleic acid (DNA) was extracted from the supernatant, and blood and tumor tissues were collected to detect patients’ EGFR gene mutation status. RESULTS: Of the 29 enrolled patients, 12 of the 23 tissue-biopsy patients (52.2%) were positive for EGFR mutations, 11 of the 28 blood-test patients (39.2%) were positive for EGFR mutations, and 13 of the 29 cases of the BALF-test patients (44.8%) were positive for EGFR mutations. The most common mutations were the exon 19 deletion mutation and the L858R point mutation. The EGFR gene mutation rate was higher in female, young, non-smoker, and stage IIIB patients (than stage IV patients), but the differences were not statistically significant (all P>0.05). Of the 29 NSCLC patients tested for the EGFR gene mutation, the BALF supernatant and blood results were the same for 27 patients (coincidence rate: 93.10%). Of the 23 of the 29 enrolled patients tested for the EGFR gene mutation, the BALF supernatant and tissue test results were the same for 21 patients (coincidence rate: 91.30%). Further, the blood-test and the tissue test results were the same for 20 patients (coincidence rate: 86.96%). CONCLUSIONS: The EGFR gene mutation rate was high in NSCLC patients. The coincidence rate of the EGFR gene mutation detection results between BALF supernatant and tumor tissues was slightly higher than that of the blood and tumor tissue EGFR gene mutation detection results.