伊马替尼停药后复发胃肠道间质瘤的临床特征与KIT/PDGFR基因突变分析

Clinical Characteristics and KIT/PDGFRα Gene Mutation of Recurrent Gastrointestinal Stromal Tumors after Imatinib Withdrawal

目的探讨转移性胃肠道间质肿瘤(GIST)患者术后伊马替尼辅助治疗过程中,停药与复发的关系,以及KIT第11外显子突变的患者复发后,对伊马替尼的敏感性研究和预后监测。方法对GIST患者复发前后临床特征进行分析比较;利用免疫组织化学的方法辅助诊断和分析复发前后CD117,CD34等GIST细胞标志物的表达情况;采用基因测序的方法进行KIT/PDGFR基因突变检测。结果 GIST患者术后,规范伊马替尼治疗3年,停药后1年余腹部包块证实为GIST复发;患者KIT基因第11外显子检测出有缺失突变:c.1667_1672delAGTGGA,提示该患者仍然对伊马替尼敏感;对于诊断GIST,DOG1比CD34更敏感。结论伊马替尼的连续用药延长无进展生存时间及延缓GIST复发,DOG1具有比CD34更好的敏感性,更加适合作为GIST的诊断标记物。

Objective To investigate the relationship between imatinib withdrawal and recurrence in a patient with metastatic gastrointestinal stromal tumor（GIST） after surgery,and to figure out whether this kind of patients were still sensitive to imatinib after the second surgery.Methods The clinical characteristics before and after the recurrence were compared.The cell bio-markers of GIST in the patient before and after the recurrence were analyzed by immunohistochemistry.Meanwhile,KIT/PDGFR gene mutations was detected through DNA sequencing.Results The patient received a standard imatinib treatment for three years after surgery,and then he terminated this medical therapy by himself.About one year later,he suffered from an abdominal mass which was confirmed to be GIST recurrence by pathological examination.A KIT deletion mutation in exon 11 was detected： c.1667_1672delAGTGGA,which suggested that the patient was still sensitive to imatinib.Through comparing the pathological results,it showed that DOG1 was more sensitive than CD34.Conclusion Patients with GIST can benefit from continuous imatinib treatment by delaying the recurrence and prolonging the progression-free survival time,and DOG1 is more sensitive than CD34 in diagnosis of GIST.