title: Benefit of adjuvant chemotherapy in patients with T4 UICC II colon cancer.
abstract: BACKGROUND
  Colorectal cancer is the third most common cancer and a major cause of morbidity and mortality worldwide. Adjuvant chemotherapy is considered the standard of care in patients with UICC stage III colon cancer after R0 resection. Adjuvant therapy was not shown to be beneficial in patients with UICC stage II colon cancer. However, there is an ongoing discussion as to whether adjuvant chemotherapy may be beneficial for a subgroup of UICC II patients in a "high-risk situation" (such as T4).
  
  
  METHODS
  We investigated a Bavarian population-based (2.1 million inhabitants) cohort of 1937 patients with UICC II CRC treated between 2002 and 2012 in regard of the benefit of adjuvant chemotherapy for large (T4) tumors. Patients older than 80 years of age were excluded. Of 1937 patients, 240 had a T4 tumor (12%); 77 of all T4 patients received postoperative chemotherapy (33%). Kaplan-Meier analysis and Cox regression models were used for survival analyses.
  
  
  RESULTS
  Patients with a T4 tumor who received postoperative chemotherapy had a highly significant survival benefit in respect of overall survival (p<0.001) and recurrence-free survival (p=0.008). However, no difference was observed between oxaliplatin-containing and non-oxaliplatin-containing treatment regimens. G2 and G3 tumors were found to particularly benefit from adjuvant treatment. Chemotherapy, age at diagnosis, and tumor grading remained independent risk factors in the multivariate cox regression analysis.
  
  
  CONCLUSIONS
  Our retrospective study demonstrated the significant benefit of adjuvant chemotherapy in the T4 subgroup of patients with UICC II colon cancer. Our data suggest that adjuvant chemotherapy should be seriously considered in these patients.
authors.affiliation: Department of Medicine I, University of Regensburg, Regensburg, Germany. andreas.teufel@ukr.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Teufel
authors.affiliation: Tumor Center, University of Regensburg, Regensburg, Germany. michael.gerken@ukr.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Gerken
authors.affiliation: Department of Medicine I, University of Regensburg, Regensburg, Germany. janine.hartl@ukr.de.
authors.forename: Janine
authors.initials: J
authors.lastname: Hartl
authors.affiliation: Department of Medicine I, University of Regensburg, Regensburg, Germany. timo.itzel@ukr.de.
authors.forename: Timo
authors.initials: T
authors.lastname: Itzel
authors.affiliation: Department of Surgery, University of Regensburg, Regensburg, Germany. stefan.fichtner@ukr.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fichtner-Feigl
authors.affiliation: Department of Radiology, University of Regensburg, Regensburg, Germany. christian.Stroszczynski@ukr.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Stroszczynski
authors.affiliation: Department of Surgery, University of Regensburg, Regensburg, Germany. hans.schlitt@ukr.de.
authors.forename: Hans Jürgen
authors.initials: HJ
authors.lastname: Schlitt
authors.affiliation: Tumor Center, University of Regensburg, Regensburg, Germany. ferdinand.hostaedter@ukr.de.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Hofstädter
authors.affiliation: Tumor Center, University of Regensburg, Regensburg, Germany. monika.klinikhammer-schalke@ukr.de.
authors.forename: Monika
authors.initials: M
authors.lastname: Klinkhammer-Schalke
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D000367:Age Factors; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D005472:Fluorouracil