title: Inhibition of HER2/estrogen receptor cross-talk, probable relation to prolonged remission of stage IV breast cancer: a case report.
abstract: Metastatic breast cancer to the liver is considered incurable. Though many patients with liver metastases may enjoy response to chemo-, immuno- and hormonal therapy, those so inflicted rarely remain disease-free from the time of diagnosis for longer than 6-11 months. New laboratory and clinical research identified that cross-talk between activation of the epidermal growth factor family of tyrosine kinase transduction pathways (EGF/HER2) and estrogen receptor (ER) activation plays a role in resistance to hormonal therapy. A 59-year-old woman with a 4.5-cm invasive ductal, ER-positive/PR-negative, grade III adenocarcinoma of the breast was treated with mastectomy. Staging revealed biopsy-proven liver metastases. Surgery was immediately followed with vinorelbine, trastuzumab, tamoxifen and exemestane. The patient underwent a bone scan and PET/CT documented complete remission. She has remained in complete remission for 7 years. It is proposed that a possible mechanism for prolonged remission of stage IV breast cancer in this patient may be related to suppression of EGF/HER2 by trastuzumab, thus inhibiting cross-talk-associated tamoxifen/estrogen withdrawal resistance.
authors.affiliation: Whittier Cancer Research Building, 13025 Bailey Street, Suite A, Whittier, CA 90601, USA. glennmd@gmail.com
authors.forename: Glenn
authors.initials: G
authors.lastname: Tisman
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000378:metabolism* / Q000556:secondary / Q000601:surgery; D000730:Androstadienes / Q000008:administration & dosage; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000556:secondary / Q000601:surgery; D015411:Mastectomy, Modified Radical; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D020239:Receptor Cross-Talk / Q000187:drug effects*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D013629:Tamoxifen / Q000008:administration & dosage; D014057:Tomography, X-Ray Computed; D000068878:Trastuzumab; D016896:Treatment Outcome; D014747:Vinblastine / Q000008:administration & dosage / Q000031:analogs & derivatives; D000077235:Vinorelbine
chemical_list: D000730:Androstadienes; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D013629:Tamoxifen; D000068878:Trastuzumab; D014747:Vinblastine; D000077235:Vinorelbine; C508053:ERBB2 protein, human; C056516:exemestane