title: HER2-positive breast cancer: ¹⁸F-FDG PET for early prediction of response to trastuzumab plus taxane-based neoadjuvant chemotherapy.
abstract: OBJECTIVE
  To investigate the value of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET/CT) to predict a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) in women with human epidermal growth factor receptor 2 (HER2)-positive breast cancer.
  
  
  METHODS
  Fifty-seven consecutive women with HER2-positive breast cancer, treated with trastuzumab plus taxane-based NAC, were prospectively included. Maximum Standardized Uptake Value of the primary tumor and axillary nodes were measured at baseline (PET₁.SUVmax) and after the first course of NAC (PET₂.SUVmax). Tumor metabolic volumes were assessed to determine Total Lesion Glycolysis (TLG). The tumor metabolic response (ΔSUVmax and ΔTLG) was calculated.
  
  
  RESULTS
  In univariate analysis, negative hormonal receptor status (p = 0.04), high tumor grade (p = 0.03), and low tumor PET₂.SUVmax (p = 0.001) were predictive of pCR. Tumor ΔSUVmax correlated with pCR (p = 0.03), provided that tumors with low metabolic activity at baseline were excluded. ΔTLG did not correlate with pCR. In multivariate analysis, tumor PET₂.SUVmax < 2.1 was the best independent predictive factor (Odds ratio =14.3; p = 0.004) with both negative and positive predictive values of 76 %. Although the metabolic features of the primary tumor did not depend on hormonal receptor status, both the baseline metabolism and early response of axillary nodes were higher if estrogen receptors were not expressed (p = 0.01 and p = 0.03, respectively).
  
  
  CONCLUSIONS
  In HER2-positive breast cancer, very low tumor residual metabolism after the first cycle of NAC (SUVmax < 2.1) was the main predictor of pCR. These results should be further explored in multicenter studies and incorporated into the design of clinical trials.
authors.affiliation: Department of Nuclear Medicine, Centre GF Leclerc, 1 rue du Pr Marion, 21000, Dijon, France, ohumbert@cgfl.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Humbert
authors.forename: Alexandre
authors.initials: A
authors.lastname: Cochet
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Riedinger
authors.forename: Alina
authors.initials: A
authors.lastname: Berriolo-Riedinger
authors.forename: Laurent
authors.initials: L
authors.lastname: Arnould
authors.forename: Bruno
authors.initials: B
authors.lastname: Coudert
authors.forename: Isabelle
authors.initials: I
authors.lastname: Desmoulins
authors.forename: Michel
authors.initials: M
authors.lastname: Toubeau
authors.forename: Inna
authors.initials: I
authors.lastname: Dygai-Cochet
authors.forename: Séverine
authors.initials: S
authors.lastname: Guiu
authors.forename: Charles
authors.initials: C
authors.lastname: Coutant
authors.forename: Pierre
authors.initials: P
authors.lastname: Fumoleau
authors.forename: François
authors.initials: F
authors.lastname: Brunotte
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D001952:Bridged-Ring Compounds / Q000627:therapeutic use*; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D005260:Female; D019788:Fluorodeoxyglucose F18; D018734:Genes, erbB-2; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D043823:Taxoids / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D000068878:Trastuzumab; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D001952:Bridged-Ring Compounds; D019275:Radiopharmaceuticals; D043823:Taxoids; D019788:Fluorodeoxyglucose F18; C080625:taxane; D000068878:Trastuzumab