title: HER-2/neu expression in primary and metastatic breast cancer.
abstract: Introduction Trastuzumab is a highly effective therapy for the treatment of HER-2/neu positive breast cancer. To maximize benefit and minimize unnecessary toxicity, patient selection is essential. Currently HER-2/neu analysis is routinely performed only for primary invasive breast cancers, and trastuzumab therapy is recommended based on primary analysis only. Methods Using immunohistochemistry, we performed a retrospective study comparing HER-2/neu expression in original primary to subsequent metastatic breast cancers. Results Tumors from 382 patients with metastatic breast cancer were studied. In 254 cases (66%) both primary and metastatic lesions were concordant. In 90 cases the primary lesion was HER-2/neu positive with the metastatic lesion negative; whereas, in 37 cases the primary lesion was HER-2/neu negative and the metastatic lesion positive. Primary HER-2/neu immunostaining was associated with a negative predictive value of 35.7%. Although all four groups were similar at diagnosis, survival differences were noted with the best survival experienced by patients with initial primary lesions HER-2/neu negative and subsequent metastatic lesions positive. Patients with hormone receptor and HER-2/neu positive primary lesions who received tamoxifen were more likely to have HER-2/neu positive metastasis. Conclusions The significant discordance between HER-2/neu expression in primary and metastatic tumors suggests that determination of HER-2/neu status in metastatic disease should be attempted.
authors.affiliation: Department of Internal Medicine, University of Cincinnati College of Medicine, Holmes, Room 1001, Eden Avenue and Albert Sabin Way, Cincinnati, OH 45267-0565, USA. ELower@ohcmail.com
authors.forename: Elyse E
authors.initials: EE
authors.lastname: Lower
authors.forename: Eleanor
authors.initials: E
authors.lastname: Glass
authors.forename: Robbin
authors.initials: R
authors.lastname: Blau
authors.forename: Stacy
authors.initials: S
authors.lastname: Harman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000188:drug therapy / Q000235:genetics / Q000401:mortality / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000188:drug therapy / Q000235:genetics*; D009363:Neoplasm Proteins / Q000032:analysis* / Q000235:genetics; D011237:Predictive Value of Tests; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D016019:Survival Analysis; D013629:Tamoxifen / Q000008:administration & dosage; D000068878:Trastuzumab; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D018719:Erb-b2 Receptor Tyrosine Kinases; D013629:Tamoxifen; D000068878:Trastuzumab