title: Proposal to subclassify stage IV gastric cancer into IVA, IVB, and IVM.
abstract: OBJECTIVE
  This study examined the prognosis of patients with stage IV gastric cancer by subgroups after surgical treatment.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Tertiary care referral center.
  
  
  METHODS
  A total of 1056 patients with stage IV gastric cancer who underwent gastrectomy from January 1, 1995, through December 31, 2006, were divided into the following 3 groups: T4N1-3M0 (group 1), T1-3N3M0 (group 2), and T(any)N(any)M1 (group 3).
  
  
  METHODS
  The clinicopathological characteristics, recurrence pattern, and survival were compared among the 3 groups.
  
  
  RESULTS
  There was a significant difference in the surgical curability, operation type, Lauren classification, histological differentiation, lymphatic invasion, number of lymph nodes retrieved, and adjuvant therapy among the 3 groups. The 5-year survival rates in groups 1, 2, and 3 were 18.3%, 27.1%, and 9.3%, respectively (P < .001). After R0 resection, locoregional recurrence (40.9%) followed by peritoneal recurrence (27.3%) was most common in group 1, whereas distant (30.2%) and peritoneal recurrence (26.7%) were most common in group 2. Multivariate analysis showed the following significant prognostic factors for survival: surgical curability and adjuvant therapy for group 1; surgical curability, surgical extent, adjuvant therapy, and number of retrieved lymph nodes for group 2; and surgical extent and chemotherapy for group 3.
  
  
  CONCLUSIONS
  Each subgroup of stage IV gastric cancer had different clinical outcomes, including histological behavior, recurrence pattern, survival, and prognostic factors. Therefore, subclassification of stage IV gastric cancer into IVA (T1-3N3M0), IVB (T4N1-3M0), and IVM (T[any]N[any]M1) might be useful for a more accurate prediction of prognosis and selection of appropriate therapeutic options.
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, Korea 135-710.
authors.forename: Ji Yeong
authors.initials: JY
authors.lastname: An
authors.forename: Tae Kyung
authors.initials: TK
authors.lastname: Ha
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Noh
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Sohn
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000145:classification* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016019:Survival Analysis; D015996:Survival Rate