title: Early tumor shrinkage in patients with metastatic colorectal cancer receiving first-line treatment with cetuximab combined with either CAPIRI or CAPOX: an analysis of the German AIO KRK 0104 trial.
abstract: OBJECTIVE
  This study investigated the impact of early tumor shrinkage (ETS) on progression-free- (PFS) and overall survival (OS) in patients with metastatic colorectal cancer (mCRC) treated within the AIO KRK 0104 trial as first-line therapy. Moreover, correlations of ETS with clinical characteristics and prognostic markers were evaluated.
  
  
  METHODS
  In total, 121 patients were included into this analysis. Patients were treated with cetuximab combined with either CAPIRI or CAPOX. ETS at six weeks was defined as a relative change of ≥ 20% in the sum of the longest diameters of target lesions compared to baseline. Survival times were compared between patients with ETS ≥ 20% versus no-ETS.
  
  
  RESULTS
  ETS ≥ 20% was observed in 59% of all patients with KRAS wild-type tumors. In these patients ETS ≥ 20% was associated with higher overall response rate (82% vs. 19%, p < 0.001). Also, PFS (8.9 vs. 4.7 months, p < 0.001) and OS (31.6 vs. 15.8 months, p = 0.005) were significantly superior in ETS ≥ 20% of patients compared to no-ETS. In patients with KRAS mutant mCRC ETS ≥ 20% neither had an effect on PFS nor OS. Cetuximab-induced skin toxicity correlated with the occurrence of ETS ≥ 20% (p = 0.002).
  
  
  CONCLUSIONS
  In patients with KRAS wild-type tumors treated with cetuximab plus capecitabine-based chemotherapy ETS ≥ 20% is an important predictor of favorable outcome.
authors.affiliation: Department of Medicine III and Comprehensive Cancer Center, University of Munich, Munich, Germany.
authors.forename: Dominik P
authors.initials: DP
authors.lastname: Modest
authors.forename: Ruediger P
authors.initials: RP
authors.lastname: Laubender
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stintzing
authors.forename: Clemens
authors.initials: C
authors.lastname: Giessen
authors.forename: Christoph
authors.initials: C
authors.lastname: Schulz
authors.forename: Michael
authors.initials: M
authors.lastname: Haas
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mansmann
authors.forename: Volker
authors.initials: V
authors.lastname: Heinemann
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D000069287:Capecitabine; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D018572:Disease-Free Survival; D004338:Drug Combinations; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D016896:Treatment Outcome; D047368:Tumor Burden; D018631:ras Proteins / Q000235:genetics
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D004338:Drug Combinations; C117307:KRAS protein, human; D009944:Organoplatinum Compounds; D011518:Proto-Oncogene Proteins; D000077150:Oxaliplatin; D003841:Deoxycytidine; D000069287:Capecitabine; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab; D005472:Fluorouracil; D002166:Camptothecin