title: Prognostic significance of smoking in addition to established risk factors in patients with Dukes B and C colorectal cancer: a retrospective analysis.
abstract: OBJECTIVE
  To investigate the prognostic significance of smoking in addition to established risk factors in patients with Dukes stage B and C colorectal cancer (CRC).
  
  
  METHODS
  291 consecutive non-selected CRC patients were studied retrospectively. Twenty-three variables were examined using a regression statistical model to identify relevant prognostic factors related to disease free survival (DFS) and overall survival (OS).
  
  
  RESULTS
  On multivariate analysis DFS was found to be negatively affected in patients with a smoking history of ≤10 pack-years vs. non-smokers (p<0.016). Additionally, performance status (PS)<90 (p<0.001), Dukes stage C (p<0.001) and elevated tumor markers (p<0.001) at the time of diagnosis were found to adversely affect DFS. Smoking also had a significant association with relapse. Patients with a smoking history of ≤10 pack-years had 2.45 (p<0.018) higher risk of recurrence compared to patients with no smoking history. OS was influenced by Karnofsky performance status (PS), Dukes stage, and elevated tumor markers. In particular patients with PS< 90 had a 4.69-fold higher risk of death (p<0.001) than patients with better PS. Stage C disease was associated with 2.27-fold higher risk of death (p<0.001) than stage B disease, and patients with elevated tumor markers at the time of diagnosis had 2.74-fold higher risk of death (p<0.014) when compared to those whose tumor markers were normal at presentation.
  
  
  CONCLUSIONS
  Our study associates smoking and relapse incidence in non-clinical- trial CRC patients and reiterates the prognostic significance of PS, stage and tumor markers at the time of diagnosis.
authors.affiliation: Department of Pathophysiology, National and Kapodistrian University of Athens, Athens, Greece. ndiamantis365@hotmail.com
authors.forename: N
authors.initials: N
authors.lastname: Diamantis
authors.forename: I D
authors.initials: ID
authors.lastname: Xynos
authors.forename: S
authors.initials: S
authors.lastname: Amptulah
authors.forename: M
authors.initials: M
authors.lastname: Karadima
authors.forename: H
authors.initials: H
authors.lastname: Skopelitis
authors.forename: N
authors.initials: N
authors.lastname: Tsavaris
mesh_terms: D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D017024:Chemotherapy, Adjuvant; D016009:Chi-Square Distribution; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D017567:Karnofsky Performance Status; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D005472:Fluorouracil