[Mutation status of epidermal growth factor receptor and KRAS gene in non-small cell lung cancers at Xuanwei regions of Yunnan Province].

OBJECTIVE

To investigate the mutation status of epidermal growth factor receptor (EGFR) and KRAS gene in patients with non-small cell lung cancer (NSCLC) in Xuanwei, Yunnan and to correlate the mutation status with clinicopathologic features.

METHODS

Mutation status of exons 18, 19, 20 and 21 of EGFR, and codons 12, 13 of KRAS in 63 cases of NSCLC were analyzed by gene sequencing and ARMS-Taqman probe method. Correlation with patients' clinicopathological characteristics was performed.

RESULTS

EGFR and KRAS mutations were present in 55.6% (35/63) and 6.3% (4/63), respectively. EGFR gene mutations were present, including exon 18 G719X in 14.3% (5/35), exon 19 in 14.3% (5/35), exon 20 S768I and T790M in 20.0% (7/35), exon 21 L858R in 31.4% (11/35), exon 18 G719X and exon 20 S768I double mutation in 17.1% (6/35), and exon 20 T790M and exon 21 L858R double mutation in 2.9% (1/35). KRAS mutations were seen in codon 12 in 3 of 4 cases, and codon 13 in 1 of 4 cases. EGFR mutations were mutually exclusive with KRAS mutations. According to statistic analysis, EGFR mutations were associated with the histological types of NSCLC(P<0.05), but without correlation with patient's gender, age, smoking status and lymph node metastasis(P>0.05). KRAS mutations in NSCLC had no correlation with the clinical pathologic characteristics of the patients.

CONCLUSIONS

A higher frequency of EGFR exon 18 G719X and 20 exon S768I mutations are found in the patients in Xuanwei, Yunnan. EGFR mutations are associated with histologic types of NSCLC, but without correlation with patient's gender, age, smoking status and lymph node metastasis. KRAS mutation in NSCLC has no correlation with the clinicopathologic characteristics of the patients.