Terada Tadashi
Department of Pathology, Shizuoka City Shimizu Hospital, Shizuoka, Japan.
Int J Clin Exp Pathol. 2012;5(4):331-8. Epub 2012 Apr 16.
KIT and PDGFRA in small cell lung carcinoma (SCLC) have been rarely examined in Japanese. The author investigated protein expression of KIT and PDGFRA in 54 Japanese cases of small cell lung carcinoma by immunohistochemistry, and gene mutations of KIT and PDGFRA in 20 Japanese cases of small cell lung carcinoma by the PCR-direct sequencing method. The molecular genetic analysis showed no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes in all 20 cases. KIT protein expression was recognized in all cases (100%). Membranous KIT expression was strong in 35 cases, moderate in 7 cases and weak in 12 cases. PDGFRA protein expression was noted in 35 cases (65%); the membranous expression was strong in 2 cases, moderate in 16 cases, and weak in 17 cases. The overall median survival was 13 months. There was no significant difference in the survival between KIT strongly positive cases (median, 12 months) and KIT moderately or weakly positive cases (median, 11 months). Likewise, there was no significant difference in the survival between PDGFRA-positive cases (median, 11 months) and PDGFRA-negative cases (median, 12 months). The protein expressions of KIT and PDGFRA did not correlate with gender, smoking, and disease stage. These findings suggest, in Japanese population, that mutations of KIT and PDGFRA were absent in small cell lung carcinoma of Japan, that KIT protein expression is present in 100%, that PDGFRA expression is present in 65%, and that KIT and PDGFRA protein expressions do not correlate with survival, gender, smoking, and disease stage.
在日本，小细胞肺癌（SCLC）中KIT和PDGFRA的研究较少。作者通过免疫组织化学法调查了54例日本小细胞肺癌病例中KIT和PDGFRA的蛋白表达情况，并通过PCR直接测序法检测了20例日本小细胞肺癌病例中KIT和PDGFRA的基因突变情况。分子遗传学分析显示，所有20例病例中KIT基因（外显子9、11、13和17）和PDGFRA基因（外显子12和18）均无突变。所有病例（100%）均检测到KIT蛋白表达。35例病例中KIT膜表达强，7例中等，12例弱。35例病例（65%）检测到PDGFRA蛋白表达；2例膜表达强，16例中等，17例弱。总体中位生存期为13个月。KIT强阳性病例（中位生存期12个月）与KIT中度或弱阳性病例（中位生存期11个月）的生存期无显著差异。同样，PDGFRA阳性病例（中位生存期11个月）与PDGFRA阴性病例（中位生存期12个月）的生存期也无显著差异。KIT和PDGFRA的蛋白表达与性别、吸烟及疾病分期无关。这些研究结果表明，在日本人群中，日本小细胞肺癌不存在KIT和PDGFRA突变，KIT蛋白表达率为100%，PDGFRA表达率为65%，且KIT和PDGFRA蛋白表达与生存期、性别、吸烟及疾病分期无关。
