Somatic mutation of KIT is rare in small cell lung cancer patients from Northeast China.

Studies have confirmed that protein overexpression or mutations of KIT are involved in growth and development of a variety of cancers. however, little is known about data of gene mutation and protein expression in small cell lung cancer (SCLC) patients from northeast China.The aim of study is to investigate gene mutation and protein expression in such patients with small cell lung cancer (SCLC) and analyse their clinical significance.The expression of c-Kit protein was analyzed by immunohistochemistry in 77 SCLC samples and 22 normal lung samples. KIT mutations were screened in exons 9, 11, 13, 14, 17 and 18 by DNA direct sequencing.The study showed that positive staining for c-Kit was observed in 28 of 77 SCLC patients . There was no correlations between expression of c-Kit and sex, ages, smoking status, stage. only 1 case was found to have known T801I mutation in exon 17. The median survival (13.9 months) of cases with c-Kit-positive was shorter than that (19.9 months) of cases with c-Kit-negative. The finding revealed that stages was identified as an independent predictive factor for SCLC patients.Our finding reveals that somatic mutation of KIT is rare in SCLC patients from the northeast China and there is no enough evidence comfirming KIT inhibitors for treatment in SCLC.