FISH及RNA测序在高级别子宫内膜间质肉瘤中的诊断价值探索

The diagnostic value of FISH and RNA sequencing in high-grade endometrial stromal sarcoma

目的探讨高级别子宫内膜间质肉瘤(HG-ESS)分子异常的致癌机制。方法回顾性分析21例HG-ESS患者的临床病理资料,使用YWHAE单融合易位探针对肿瘤组织样本进行荧光原位杂交(FISH)。对于肿瘤组织可及的5例样本进行RNA测序以验证融合状态,对其中检出YWHAE-NUTM2B融合的样本进行免疫组织化学(IHC)和免疫荧光(IF)检测以验证是否为功能性融合,并基于Kaplan-Meier法和log-rank检验对YWHAE融合阳性与阴性亚组进行生存分析。结果21例HG-ESS患者平均确诊年龄(46.1±12.6)岁,均出现阴道异常流血症状。FISH检测结果为阴性11例,阳性7例,不典型3例。组织可及的5例样本RNA测序结果提示在1例FISH阳性和1例FISH不典型患者中检出YWHAE-NUTM2B融合,3例FISH阴性样本未检出融合。经IHC和IF检测确认2例RNA测序阳性患者中该融合基因产物(14-3-3ε)核表达。Kaplan-Meier生存曲线提示YWHAE融合阳性组生存略优于阴性组,但两组差异无统计学意义(P>0.05)。结论FISH和RNA测序是辅助诊断HG-ESS的有效技术,对于YWHAE融合检测FISH结果为阴性或不典型的HG-ESS患者,应进行RNA测序进一步确认YWHAE融合或其他特异性结构变异。

Objective To investigate the carcinogenic mechanisms of molecular abnormalities in high-grade endometrial stromal sarcoma(HG-ESS).Methods The clinicopathological data of 21 patients with HG-ESS were retrospectively analyzed.Fluorescence in situ hybridization(FISH)was performed on the tumor samples using YWHAE single fusion translocation probe.RNA sequencing was performed on 5 patients with accessible tumor tissues to verify the fusion status.Immunohistochemistry(IHC)and immunofluorescence(IF)were performed for patients with YWHAE-NUTM2B fusion to verify the fusion function.Based on Kaplan-Meier method and log-rank test,survival analysis was performed on patients with positive and negative YWHAE fusion.Results The average age at diagnosis of the 21 HG-ESS patients was(46.1±12.6)years old,and HG-ESS patients all had abnormal vaginal bleeding symptom.FISH results of 21 HG-ESS patients were negative in 11 cases,positive in 7 cases,and atypical in 3 cases.The RNA sequencing results of 5 accessible tissue samples showed that YWHAE-NUTM2B typical fusion was detected in 1 FISH-positive and 1 FISH-atypical patient,and no fusion was detected in 3 FISH-negative samples.The nuclear expression of the fusion gene product(14-3-3ε)was confirmed by IHC and IF in two cases with YWHAE-NUTM2B fusion detected using RNA sequencing.Kaplan-Meier survival curve suggested that the YWHAE fusion positive group survived slightly better than the YWHAE fusion negative group,but the difference between these two groups was not statistically significant(P>0.05).Conclusions FISH and RNA sequencing methods are effective techniques for differential diagnosis of HG-ESS.RNA sequencing should be performed in HG-ESS patients with negative and atypical YWHAE fusion FISH results to check the presence of YWHAE fusion or other specific structural variants.