title: Survival Outcome and Risk of Metachronous Colorectal Cancer After Surgery in Lynch Syndrome.
abstract: BACKGROUND
  The survival benefit of extensive colectomy is controversial in Lynch syndrome, and risk factors for metachronous colorectal cancer (CRC) after segmental colectomy are unclear.
  
  
  OBJECTIVE
  The aim of this study was to investigate the survival outcome and risk of metachronous CRC after surgery in Lynch syndrome patients diagnosed with their first CRC.
  
  
  METHODS
  Overall, 106 patients with Lynch syndrome who underwent surgery for CRC were included in the study. The demographics, genotype, clinicopathological characteristics of the index CRC, and follow-up data were reviewed from a single-institution Lynch syndrome database.
  
  
  RESULTS
  Of 30 patients who underwent extensive surgery, no metachronous CRC was developed during a mean follow-up of 68.1 months. Of 76 patients who underwent segmental colectomy, 13 (17.1 %) developed metachronous CRC during a mean follow-up of 77.2 months. The cumulative risk of metachronous CRC was 8.4 % at 5 years and 20.4 % at 10 years after segmental colectomy. No difference in overall and CRC-specific survival was observed between segmental colectomy and extensive colectomy (p = 0.277 and p = 0.659, respectively). A 25 cm or longer resection of bowel decreased the risk of metachronous CRC after segmental colectomy compared with less extensive resection (hazard ratio 0.10, 95 % confidence interval 0.01-0.86). Annual surveillance colonoscopy did not decrease the risk of metachronous CRC compared with less frequent surveillance colonoscopy. Although not statistically significant, none of the MSH6 gene mutation carriers were diagnosed with metachronous CRC.
  
  
  CONCLUSIONS
  Although no survival benefit was identified, surgeons and patients might consider extensive colectomy to prevent metachronous CRC in Lynch syndrome patients regardless of their clinicopathological characteristics.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Tae Jun
authors.initials: TJ
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Ran
authors.initials: ER
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Noh
authors.initials: SN
authors.lastname: Hong
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jung Wook
authors.initials: JW
authors.lastname: Huh
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yoon Ah
authors.initials: YA
authors.lastname: Park
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yong Beom
authors.initials: YB
authors.lastname: Cho
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seong Hyeon
authors.initials: SH
authors.lastname: Yun
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hee Cheol
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Woo Yong
authors.initials: WY
authors.lastname: Lee
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kiyoun
authors.initials: K
authors.lastname: Kim
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyunga
authors.initials: K
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. dkchang@skku.edu.
authors.forename: Dong Kyung
authors.initials: DK
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy / Q000379:methods*; D003113:Colonoscopy; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D018095:Germ-Line Mutation; D006801:Humans; D015994:Incidence; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D000070957:MutL Protein Homolog 1 / Q000235:genetics; D051718:MutS Homolog 2 Protein / Q000235:genetics; D016609:Neoplasms, Second Primary / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D011159:Population Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein