title: The initial change in tumor size predicts response and survival in patients with metastatic colorectal cancer treated with combination chemotherapy.
abstract: BACKGROUND
  To determine whether the change in tumor diameters at the first follow-up computed tomography (CT) examination after baseline examination (first change) correlates with outcome in patients with metastatic colorectal cancer (mCRC) treated with combination chemotherapy.
  
  
  METHODS
  The first change was analyzed in a multicenter randomized phase III trial (Nordic VI, N = 567) comparing first-line irinotecan with either bolus or infused 5-fluorouracil. Cox proportional hazards multiple regression model and Kaplan-Meier survival analyses after correction for guarantee-time bias were carried out to evaluate correlations between first change, objective response according to RECIST 1.0, progression-free survival (PFS), and overall survival (OS).
  
  
  RESULTS
  The hazard ratios for PFS and OS decreased along with first change. A decrease between 10% and <30%, albeit RECIST does not regard this as a partial response, was a positive prognostic factor for PFS and OS. Patients who had new lesions or unequivocal progression of nonmeasurable lesions had a worse prognosis than those with only an increase in size of >20%.
  
  
  CONCLUSIONS
  The change in tumor size at the first follow-up CT is strongly prognostic for PFS and OS in mCRC.
authors.affiliation: Department of Diagnostic Radiology, Institution for Molecular Medicine and Surgery, Karolinska University Hospital Solna and Karolinska Institutet, Stockholm, Sweden. Chikako.Suzuki@ki.se
authors.forename: C
authors.initials: C
authors.lastname: Suzuki
authors.forename: L
authors.initials: L
authors.lastname: Blomqvist
authors.forename: A
authors.initials: A
authors.lastname: Sundin
authors.forename: H
authors.initials: H
authors.lastname: Jacobsson
authors.forename: P
authors.initials: P
authors.lastname: Byström
authors.forename: Å
authors.initials: Å
authors.lastname: Berglund
authors.forename: P
authors.initials: P
authors.lastname: Nygren
authors.forename: B
authors.initials: B
authors.lastname: Glimelius
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D000077146:Irinotecan; D053208:Kaplan-Meier Estimate; D002955:Leucovorin / Q000008:administration & dosage; D008113:Liver Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000556:secondary*; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000556:secondary*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects*
chemical_list: D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin