title: Adjuvant chemotherapy and prognostic factors in stage II colon cancer--Izmir Oncology Group Study.
abstract: BACKGROUND
  Although adjuvant chemotherapy is a standard treatment in stage III colon cancer, its benefit is not as clear for stage II patients. In this retrospective analysis, we aimed to evaluate the survival of patients with low-risk stage II colon cancer, the efficacy of adjuvant chemotherapy in high-risk stage II colon cancer patients, and prognostic factors in stage II disease.
  
  
  METHODS
  One hundred and seventeen patients who were diagnosed with stage II colon cancer between January 2006 and December 2011 were included in the study. Patients were stratified into two groups as being low-risk and high-risk according to risk factors for stage II disease. Adjuvant 5-fluorouracil-based chemotherapy were administered to the patients with risk factors.
  
  
  RESULTS
  Ninety-four patients were treated with adjuvant chemotherapy due to high risk factors and 23 were monitored without treatment. Median follow-up time was 43 months. In terms of disease free survival and overall survival, adjuvant chemotherapy did not provide a statistically significant difference. Univariate analysis demonstrated that bowel obstruction was the major risk factor for shortened disease-free survival, while bowel perforation and perineural invasion were both negative prognostic factors for overall survival.
  
  
  CONCLUSIONS
  The recommendation of adjuvant chemotherapy for stage II colon cancer is not clear. In our study, it was found that adjuvant chemotherapy did not contribute to survival in high-risk stage II patients. Due to the fact that prognosis of stage II patients is good, many more patients will be needed for statistically significant differences in survival. Adjuvant chemotherapy containing 5 fluorouracil is being used to high-risk stage II patients although it is not a standard treatment approach.
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey E-mail : drzeybek@yahoo.com.
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Kucukzeybek
authors.forename: Ahmet
authors.initials: A
authors.lastname: Dirican
authors.forename: Lutfiye
authors.initials: L
authors.lastname: Demir
authors.forename: Serkan
authors.initials: S
authors.lastname: Yildirim
authors.forename: Murat
authors.initials: M
authors.lastname: Akyol
authors.forename: Yasar
authors.initials: Y
authors.lastname: Yildiz
authors.forename: Ibrahim Vedat
authors.initials: IV
authors.lastname: Bayoglu
authors.forename: Ahmet
authors.initials: A
authors.lastname: Alacacioglu
authors.forename: Umut
authors.initials: U
authors.lastname: Varol
authors.forename: Tarik
authors.initials: T
authors.lastname: Salman
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Yildiz
authors.forename: Huseyin
authors.initials: H
authors.lastname: Can
authors.forename: Mustafa Oktay
authors.initials: MO
authors.lastname: Tarhan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate; D014421:Turkey
chemical_list: D002955:Leucovorin; D005472:Fluorouracil