title: Evaluation of tumor response after locoregional therapies in hepatocellular carcinoma: are response evaluation criteria in solid tumors reliable?
abstract: BACKGROUND
  Evaluation of response to treatment is a key aspect in cancer therapy. Response Evaluation Criteria in Solid Tumors (RECIST) are used in most oncology trials, but those criteria evaluate only unidimensional tumor measurements and disregard the extent of necrosis, which is the target of all effective locoregional therapies. Therefore, the European Association for the Study of the Liver (EASL) guidelines recommended that assessment of tumor response should incorporate the reduction in viable tumor burden. The current report provides an assessment of the agreement/concordance between both RECIST and the EASL guidelines for the evaluation of response to therapy.
  
  
  METHODS
  The authors evaluated a cohort of 55 patients within prospective studies, including 24 patients with hepatocellular carcinoma who underwent transarterial chemoembolization (TACE) with drug eluting beads (DEB-TACE) and 31 patients who underwent percutaneous ablation (percutaneous ethanol injection [PEI]/radiofrequency [RF]). Triphasic helical computed tomography scans were performed at baseline, at 1 month, and at 3 months after procedure, and 2 independent radiologists evaluated tumor response.
  
  
  RESULTS
  Evaluating response according to RECIST criteria, no patients achieved a complete response (CR), 21.8% of patients achieved a partial response (PR) (none in the PEI/RF group), 47.3% of patients had stable disease (SD), and 30.9% of patients had progressive disease (PD). When response was evaluated according to the EASL guidelines, 54.5% of patients achieved a CR, 27.3% of patients achieved a PR, 3.6% of patients had SD, and 14.5% had PD. The kappa coefficient was 0.193 (95% confidence interval, 0.0893-0.2967; P < .0001).
  
  
  CONCLUSIONS
  RECIST missed all CRs and underestimated the extent of partial tumor response because of tissue necrosis, wrongly assessing the therapeutic efficacy of locoregional therapies. This evaluation should incorporate the reduction in viable tumor burden as recognized by nonenhanced areas on dynamic imaging studies.
authors.affiliation: Liver Unit, Barcelona Clinic Liver Cancer (BCLC) Group, Hospital Clinic, August Pi i. Sunyer Institute of Biomedical Investigations, Biomedical Center for Research into Hepatic and Digestive Diseases (CIBEREHD), University of Barcelona, Barcelona, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Forner
authors.forename: Carmen
authors.initials: C
authors.lastname: Ayuso
authors.forename: María
authors.initials: M
authors.lastname: Varela
authors.forename: Jordi
authors.initials: J
authors.lastname: Rimola
authors.forename: Amelia J
authors.initials: AJ
authors.lastname: Hessheimer
authors.forename: Carlos Rodriguez
authors.initials: CR
authors.lastname: de Lope
authors.forename: María
authors.initials: M
authors.lastname: Reig
authors.forename: Luís
authors.initials: L
authors.lastname: Bianchi
authors.forename: Josep M
authors.initials: JM
authors.lastname: Llovet
authors.forename: Jordi
authors.initials: J
authors.lastname: Bruix
mesh_terms: D000279:Administration, Cutaneous; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000628:therapy*; D017115:Catheter Ablation; D015331:Cohort Studies; D004621:Embolization, Therapeutic; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000628:therapy*; D017063:Outcome Assessment, Health Care; D015203:Reproducibility of Results; D016896:Treatment Outcome; D047368:Tumor Burden