title: Value of tumor size as a prognostic variable in colorectal cancer: a critical reappraisal.
abstract: OBJECTIVE
  Vertical tumor growth, reflected by T classification, represents the most important prognostic variable in colorectal cancer. Our study aimed to investigate the impact of tumor size, particularly the maximum tumor diameter, on outcome of affected patients.
  
  
  METHODS
  A total of 381 colorectal cancer specimens were re-evaluated. Tumor size and location were extracted from the medical history and were known for 359 patients (94%). Receiver-operator characteristic analysis was applied to identify the optimal (maximum of sum of sensitivity and specificity) cut-off values with respect to prognostic impact.
  
  
  RESULTS
  Median tumor size was 4.5 cm (range, 0.6-15). Tumor size exceeding 4.5 cm was observed in 159 patients (44%) and was associated with high T and N classification, UICC stage, and tumor grade. At median follow-up of 45 months (range, 0-180), 141 patients (40%) showed tumor progression. Although 4.5 cm was identified as the optimal cut-off value within the whole group of patients, receiver-operator characteristic analysis restricted to different parts of the large bowel determined 5 cm, 5.3 cm, 3.9 cm, and 3.4 cm as cut-off values with the strongest discriminatory capacity in colon, right-sided colon, left-sided colon, and rectum cancers, respectively. Applying these cut-off values, tumor size was significantly associated with progression-free and cancer-specific survival in univariate and multivariate analyses in colon, yet not in rectum cancers.
  
  
  CONCLUSIONS
  Tumor size proved to be an independent prognostic parameter for patients with colorectal cancer. Optimal cut-off values vary among different parts of the large bowel. Whereas prognostic significance is strong within the colon, it appears to be of minor value within the rectum.
authors.affiliation: Department of Surgery, Division of General Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Kornprat
authors.forename: Marion J
authors.initials: MJ
authors.lastname: Pollheimer
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lindtner
authors.forename: Andrea
authors.initials: A
authors.lastname: Schlemmer
authors.forename: Peter
authors.initials: P
authors.lastname: Rehak
authors.forename: Cord
authors.initials: C
authors.lastname: Langner
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D011379:Prognosis; D012372:ROC Curve; D018714:Radiotherapy, Adjuvant; D012680:Sensitivity and Specificity; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor