Is Microsatellite Instability Really a Good Prognostic Factor of Colorectal Cancer?

摘要

Purpose The aim of this study was to investigate the clinicopathologic features of and the prognosis for colorectal cancers (CRCs) with microsatellite instabilities (MSIs). Methods Between 2006 and 2009, genotyping was performed on 245 patients with stage II/III CRCs to establish the MSI status. The clinicopathologic differences and the prognostic value of MSI were analyzed. The median follow-up period was 38 months (range, 7-68 months). Results Of the total 245 patients, 20 (8.2%) had MSI-high (H) and 225 (91.8%) had MSI-low (L) or stable (S) CRCs. Adjuvant chemotherapies were performed on 101 stage II (87.8%) and 107 stage III patients (82.3%). Patients with MSI-H CRCs more frequently had a family history of colon cancer (10% vs. 2.7%, P = 0.003), more frequently had a cancer located at the proximal colon (90.0% vs. 19.1%, P Conclusion MSI-H CRCs had distinct clinicopathologic features, and MSI-H was an independent poor prognostic factor in stage II CRCs. Considering the majority of stage II patients were administrated adjuvant chemotherapy, the efficacy of adjuvant chemotherapy for treating MSI CRCs might be different from that for treating MSI-L/S tumors.