title: Effects of microsatellite instability on recurrence patterns and outcomes in colorectal cancers.
abstract: Among colorectal cancers (CRCs), high-frequency microsatellite instability (MSI-H) is associated with a better prognosis, compared with low-frequency MSI or microsatellite stability (MSI-L/MSS). However, it is unclear whether MSI affects the prognosis of recurrent CRCs.
  
  
  
  This study included 2940 patients with stage I-III CRC who underwent complete resection. The associations of MSI status with recurrence patterns, disease-free survival (DFS), overall survival from diagnosis to death (OS1), and overall survival from recurrence to death (OS2) were analysed.
  
  
  
  A total of 261 patients (8.9%) had MSI-H CRC. Patients with MSI-H CRC had better DFS, compared to patients with MSI-L/MSS CRC (hazard ratio (HR): 0.619, P<0.001). High-frequency microsatellite instability CRC was associated with more frequent local recurrence (30.0% vs 12.0%, P=0.032) or peritoneal metastasis (40.0% vs 12.3%, P=0.003), and less frequent lung (10.0% vs 42.5%, P=0.004) or liver metastases (15.0% vs 44.7%, P=0.01). Recurrent MSI-H CRC was associated with worse OS1 (HR: 1.363, P=0.035) and OS2 (HR: 2.667, P<0.001). An analysis of patients with colon cancer yielded similar results.
  
  
  
  Recurrence patterns differed between MSI-H CRC and MSI-L/MSS CRC, and recurrent MSI-H CRCs had a worse prognosis.
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Chang Gon
authors.initials: CG
authors.lastname: Kim
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Joong Bae
authors.initials: JB
authors.lastname: Ahn
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Minkyu
authors.initials: M
authors.lastname: Jung
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Beom
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, CHA Bundang Medical Center, 59 Yatap-ro, Bundang-gu, Seongnam 463-712, South Korea.
authors.forename: Chan
authors.initials: C
authors.lastname: Kim
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Joo Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Heo
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Hyung Soon
authors.initials: HS
authors.lastname: Park
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Jee Hung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Byung Soh
authors.initials: BS
authors.lastname: Min
authors.affiliation: Department of Pathology, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Hoguen
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Woong Sub
authors.initials: WS
authors.lastname: Koom
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Shin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000473:pathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D055815:Young Adult