title: Distinctive oncological features of stage IIIA colorectal cancer: Analysis of prognostic factors for selective adjuvant chemotherapy.
abstract: BACKGROUND
  In the seventh TNM classification, stage IIIA includes tumors with early stage of bowel wall invasion and regional lymph node metastasis. We investigated the validity of the current TNM classification of patients with stage IIIA colorectal cancer and identified prognostic factors of them for ameliorating treatment strategies for them.
  
  
  METHODS
  This study included the participation of four tertiary hospitals. A total of 4,236 patients with Stages I-IIIB colorectal cancer were analyzed. The primary end point was the 5-year relapse-free survival.
  
  
  RESULTS
  The 5-year relapse-free survival of patients with stage IIIA disease was similar to that of patients with stage IIA. The 5-year relapse-free survival was 88.9% in the chemotherapy group (n = 152) and 82.3% in the no-chemotherapy group (n = 36, P = 0.111). Tumor differentiation (moderate or poor) and venous invasion were independent prognostic factors of relapse-free survival.
  
  
  CONCLUSIONS
  The relapse-free survival of patients with stage IIIA tumors was similar to that of patients with stage IIA tumors, and the prognosis of stage IIIA tumors varied significantly by the tumor factors identified. These factors can be used to predict the risk of disease recurrence and to optimize the use of adjuvant chemotherapy.
authors.affiliation: Colorectal Cancer Center, Kyungpook National University Medical Center, School of Medicine, Kyungpook National University, Daegu, Korea.
authors.forename: Soo Yeun
authors.initials: SY
authors.lastname: Park
authors.forename: Gyu-Seog
authors.initials: GS
authors.lastname: Choi
authors.forename: Jun Seok
authors.initials: JS
authors.lastname: Park
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Sakai
authors.forename: Suguru
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Seon Hahn
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate
keywords: adjuvant chemotherapy; colorectal cancer; prognosis; stage IIIA