交界性胃肠道间质瘤279例临床病理学分析

Borderline gastrointestinal stromal tumors:clinical and pathological studies of 279 cases

目的阐述交界性胃肠道间质瘤(gastrointestinal stromal tumors,GISTs)的特征并重新评估目前广泛应用于GISTs的美国国家卫生研究所(NIH)共识标准。方法回顾性分析840名患者的病史资料及手术切除标本。结果筛除485例恶性GISTs及76例假定的良性GISTs,剩余的279例GISTs归为交界性GISTs,其中223例随访1～31年。2例患者局部复发,随后经过单纯手术切除治愈。5年无瘤生存率和总生存率分别为99%和100%。形态学上,交界性GISTs的典型特征为富于细胞、中度异型性、低核分裂活性(<10个/50 HPF)或较大肿瘤体积。依据NIH共识标准,279例中,极低危险度组13例,低危组164例,中危组71例,高危组31例,但各组间的无瘤生存率差异无显著性(P=0.681)。结论交界性GISTs具有介于良恶性GISTs之间的临床及形态学特征。部分交界性GISTs表现出恶性潜能,需长期随访。NIH共识标准基于肿瘤体积及核分裂象划分的危险度等级并不适用于评估交界性GISTs的生物学行为。

Purpose Borderline gastrointestinal stromal tumors（GISTs） are intermediate tumors between benign and malignant variants;however,the clinical and pathological features of borderline GISTs remain poorly defined.The present study was aimed to characterize borderline GISTs and to re-evaluate the NIH consensus criteria that are often used to classify GISTs.Methods Medical records and specimens were retrospectively examined in 840 cases of GISTs.485 and 76 patients with any of the parameters predictive of either malignant or benign GISTs,respectively,were excluded.Results Among the remaining 279 borderline GIST patients,223 were followed for 1 to 31 years.Two patients developed local recurrence,and both were cured by subsequent surgical removal alone.The 5-year disease-free survival and overall survival rates were 99% and 100%,respectively.Morphologically,borderline GISTs typically exhibited moderate cellularity,and subsets of them also showed moderate atypia,low mitotic activities,or a large tumor in size.According to the NIH consensus criteria,the risk levels of these 279 GISTs were classified into very low to high.However,the disease-free survival rates were not significantly different among all these risk groups（P=0.681）.Conclusions Borderline GISTs display intermediate clinical and morphological features distinct from benign and malignant GISTs.Some borderline GISTs show malignant potential,and these patients may require long-term follow-up.The NIH criteria,primarily based on tumor size and mitotic count,are not suitable to evaluate the biological behaviors of borderline GISTs.