Clinical, Pathologic, Immunohistochemical Characteristics, Surgical Management And Prognosis Of Gastrointestinal Stromal Tumor Of The Rectum: Analysis Of 11 Cases

PURPOSE:Gastrointestinal stromal tumor which origin from rectum is rare,we review the clinical,pathologic,immunohistochemical Characteristics,Surgical management and prognosis of gastrointestinal stromal tumors of the rectum,evaluate their prognostic factors and correlate clinicopathologic findings with the subsequent clinical course,to explore ideal managements for the rectal GIST.METHODS:Patient and disease characteristics at presentation,pathologic features,surgical management,and clinical outcomes of 11 patients with rectal GIST diagnosed and treated at Sir Run Run Shaw Hospital Zhejiang University between 2003.1.1 and 2009.2.28 were evaluated.RESULTS:Tumors were classified on basis of size and mitotic rate according to National Institutes of Health Consensus Criteria for Assigning Risk to Gastrointestinal Stromal Tumors:4(4/11,36.4%) were high-risk(HR),2(2/11,18.2%) were intermediate-risk(IR),5(5/11,45.4%) were low-risk(LR).All of 11 tumors were both KIT(CD117) and CD34 positive.2 LR patients out of 11 underwent transanal resection, whereas 9 patients radical resection(2 low anterior resection and 7 abdominoperineal resection).3 out of 4 patients with high-risk rectal GIST developed metastases 20,23 and 37 months postoperatively,and died of metastatic diseases at the end,and another patient with HR was only 1 month postoperatively.1 IR patients developed local recurrence 13 months postoperatively.The other 6 patients(5 LR,1 IR) still alive without both local recurrence and metastases.CONCLUSIONS:The majority of rectal GISTs are CD117 and CD34 positive. The NIH risk classification was found to be the independent prognostic factor for rectal GISTs.Local resection may be a good choice for very-low and low-risk rectal GISTs, but aggressive surgery may be beneficial for intermediate and high -risk GISTs.Patients with high-risk tumors may benefit from postoperative imatinib adjuvant therapy.