title: Evaluation of erlotinib treatment response in non-small cell lung cancer using metabolic and anatomic criteria.
abstract: In this paper the clinical value of PET for early prediction of tumor response to erlotinib in patients with advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one prior chemotherapy regimen is evaluated. The aim was to compare the early metabolic treatment response using European Organization for Research and Treatment of Cancer (EORTC) 1999 recommendations and PET Response Criteria in Solid Tumors (PERCIST), and the standard treatment response using Response Evaluation Criteria in Solid Tumors (RECIST).
  
  
  
  Twenty patients with stage IV NSCLC were enrolled prospectively. PET/CT studies were performed before, then 48 hours, and 45 days after the initiation of erlotinib treatment. The lesion with the highest uptake in each patient was evaluated according to EORTC 1999 recommendations, PERCIST and RECIST to assess metabolic and anatomic response. Response classifications were compared statistically using Wilcoxon signed-rank test. Disease-free survival (DFS) and overall survival (OS) were calculated by the Kaplan-Meier Test.
  
  
  
  At 48 hours, the Kaplan-Meier analysis showed that EORTC proved to be a significant prognostic factor for predicting DFS and OS. At 45 days, there was a significant difference in response evaluation between RECIST and metabolic classifications. RECIST and PERCIST were significant prognostic factors for predicting DFS and OS. EORTC was not able to discriminate responder from non-responder patients.
  
  
  
  This study shows that, according to the EORTC protocol, the PET exam is able to provide early identification of patients who benefit from Erlotinib treatment. Used at the end of therapy, PERCIST could be considered an appropriate metabolic evaluation method to discriminate responders from non-responders.
authors.affiliation: IBFM CNR-LATO, Cefalu', Palermo, Italy - giorgio.russo@polooncologicocefalu.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stefano
authors.forename: Giorgio
authors.initials: G
authors.lastname: Russo
authors.forename: Massimo
authors.initials: M
authors.lastname: Ippolito
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Cosentino
authors.forename: Gabriella
authors.initials: G
authors.lastname: Murè
authors.forename: Sara
authors.initials: S
authors.lastname: Baldari
authors.forename: Maria G
authors.initials: MG
authors.lastname: Sabini
authors.forename: Daniele
authors.initials: D
authors.lastname: Sardina
authors.forename: Lucia M
authors.initials: LM
authors.lastname: Valastro
authors.forename: Roberto
authors.initials: R
authors.lastname: Bordonaro
authors.forename: Cristina
authors.initials: C
authors.lastname: Messa
authors.forename: Maria C
authors.initials: MC
authors.lastname: Gilardi
authors.forename: Hector
authors.initials: H
authors.lastname: Soto Parra
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000401:mortality; D018572:Disease-Free Survival; D000069347:Erlotinib Hydrochloride / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D000069347:Erlotinib Hydrochloride