title: Early PET/CT scan is more effective than RECIST in predicting outcome of patients with liver metastases from colorectal cancer treated with preoperative chemotherapy plus bevacizumab.
abstract: Markers predictive of treatment effect might be useful to improve the treatment of patients with metastatic solid tumors. Particularly, early changes in tumor metabolism measured by PET/CT with (18)F-FDG could predict the efficacy of treatment better than standard dimensional Response Evaluation Criteria In Solid Tumors (RECIST) response.
  
  
  METHODS
  We performed PET/CT evaluation before and after 1 cycle of treatment in patients with resectable liver metastases from colorectal cancer, within a phase 2 trial of preoperative FOLFIRI plus bevacizumab. For each lesion, the maximum standardized uptake value (SUV) and the total lesion glycolysis (TLG) were determined. On the basis of previous studies, a ≤ -50% change from baseline was used as a threshold for significant metabolic response for maximum SUV and, exploratively, for TLG. Standard RECIST response was assessed with CT after 3 mo of treatment. Pathologic response was assessed in patients undergoing resection. The association between metabolic and CT/RECIST and pathologic response was tested with the McNemar test; the ability to predict progression-free survival (PFS) and overall survival (OS) was tested with the Log-rank test and a multivariable Cox model.
  
  
  RESULTS
  Thirty-three patients were analyzed. After treatment, there was a notable decrease of all the parameters measured by PET/CT. Early metabolic PET/CT response (either SUV- or TLG-based) had a stronger, independent and statistically significant predictive value for PFS and OS than both CT/RECIST and pathologic response at multivariate analysis, although with different degrees of statistical significance. The predictive value of CT/RECIST response was not significant at multivariate analysis.
  
  
  CONCLUSIONS
  PET/CT response was significantly predictive of long-term outcomes during preoperative treatment of patients with liver metastases from colorectal cancer, and its predictive ability was higher than that of CT/RECIST response after 3 mo of treatment. Such findings need to be confirmed by larger prospective trials.
authors.affiliation: Nuclear Medicine Unit, Istituto Nazionale Tumori "Fondazione G. Pascale" - IRCCS, Naples, Italy.
authors.forename: Secondo
authors.initials: S
authors.lastname: Lastoria
authors.forename: Maria Carmela
authors.initials: MC
authors.lastname: Piccirillo
authors.forename: Corradina
authors.initials: C
authors.lastname: Caracò
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Nasti
authors.forename: Luigi
authors.initials: L
authors.lastname: Aloj
authors.forename: Cecilia
authors.initials: C
authors.lastname: Arrichiello
authors.forename: Elisabetta
authors.initials: E
authors.lastname: de Lutio di Castelguidone
authors.forename: Fabiana
authors.initials: F
authors.lastname: Tatangelo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ottaiano
authors.forename: Rosario Vincenzo
authors.initials: RV
authors.lastname: Iaffaioli
authors.forename: Francesco
authors.initials: F
authors.lastname: Izzo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Romano
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Giordano
authors.forename: Simona
authors.initials: S
authors.lastname: Signoriello
authors.forename: Ciro
authors.initials: C
authors.lastname: Gallo
authors.forename: Francesco
authors.initials: F
authors.lastname: Perrone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols; D000068258:Bevacizumab; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D057234:Preoperative Period; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068258:Bevacizumab
keywords: colorectal cancer; early PET/CT; liver metastases; predictive factor; preoperative treatment