title: Predictors of a true complete response among disappearing liver metastases from colorectal cancer after chemotherapy.
abstract: BACKGROUND
  During chemotherapy, some colorectal liver metastases (LMs) disappear on serial imaging. This disappearance may represent a complete response (CR) or a reduction in the sensitivity of imaging during chemotherapy. The objective of the current study was to determine the fate of disappearing LMs (DLMs) and the factors that predict a true CR.
  
  
  METHODS
  Between 2000 and 2003, 435 patients who were evaluated by hepatobiliary surgeons received chemotherapy before they were considered for resection. Inclusion criteria were <12 LMs before chemotherapy, at least 1 DLM on a computed tomography (CT) scan, and either surgical resection or 1 year of clinical follow-up after the disappearance of LMs. A true CR was defined as either a pathologic CR (no tumor detected in the resection specimen) or a durable clinical CR (did not reappear on follow-up imaging). Clinical and pathologic factors were analyzed to identify those associated with a true CR.
  
  
  RESULTS
  During chemotherapy, 39 patients (9%) had a total of 118 DLMs on follow-up CT scans. Sixty-eight DLMs were resected, and 50 were followed clinically. Overall, 75 DLMs (64%) were true CRs, including 44 pathologic CRs and 31 durable clinical CRs. On multivariate analysis, the use of hepatic arterial infusion (HAI) chemotherapy (odds ratio [OR], 6.2; P = .02), the inability to observe the DLM on a magnetic resonance image (OR, 4.7; P = .005), and normalization of serum carcinoembryonic antigen levels (OR, 4.6; P = .006) were associated independently with a true CR.
  
  
  CONCLUSIONS
  Approximately 66% of DLMs represented a true CR according to assessment by resection or radiologic follow-up. Predictive factors may help to stratify patients who are likely to harbor residual disease.
authors.affiliation: Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada. rauer@ohri.ca
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Auer
authors.forename: Rebekah R
authors.initials: RR
authors.lastname: White
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Kemeny
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Schwartz
authors.forename: Jinru
authors.initials: J
authors.lastname: Shia
authors.forename: Leslie H
authors.initials: LH
authors.lastname: Blumgart
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Dematteo
authors.forename: Yuman
authors.initials: Y
authors.lastname: Fong
authors.forename: William R
authors.initials: WR
authors.lastname: Jarnagin
authors.forename: Michael I
authors.initials: MI
authors.lastname: D'Angelica
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000473:pathology*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012074:Remission Induction; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome