title: The importance of tissue confirmation of metastatic disease in patients with breast cancer: lesson from a brain metastasis case.
abstract: BACKGROUND
  The discrepancy of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) statuses in breast cancers has been reported. Available systemic therapy for patients with breast cancer is based on the molecular subtypes as identified by IHC and/or FISH. However, these biomarkers may change throughout tumor progression.
  
  
  METHODS
  We report a relatively uncommon case of a 39-year-old Chinese woman with local advanced breast cancer (LABC) treated with 6 cycles of docetaxel, doxorubicin and cyclophosphamide (TAC) regimen neoadjuvant chemotherapy, and subsequently mastectomy, intensity-modulated radiation therapy (IMRT) and tamoxifen followed as regularly. Brain metastatic event appeared in 6 months after mastectomy. Treatment for brain metastasis was surgical resection and followed by whole brain radiotherapy (WBRT) approved by multidisciplinary team (MDT). Initial pathological diagnosis was IDC, cT4N1M0, luminal B (ER+ 90%, PR+90%, HER2 0, Ki67+ 70%) based on ultrasound-guided core needle biopsy. Surgical pathology revealed IDC, pT2N3M0 luminal B (ER+ 20%, PR+20%, HER2 0, Ki67+ 20%). Histological response to neoadjuvant chemotherapy is grade 3 according to the Miller/Payne grading system. Final pathology of brain metastasis showed a HER2 overexpression metastatic breast cancer luminal B (ER+ 70%, PR+ 70%, HER2 2+, Ki67+ 30%), FISH confirmed HER2 overexpression. Weekly paclitaxel plus trastuzumab was given for 12 weeks, then trastuzumab every 3 weeks for a whole year. Patient follow-up is still ongoing, no new events appear yet.
  
  
  CONCLUSIONS
  The determination of hormone receptors and HER2 status should be routinely performed in all involved tissues, if possible, and systemic therapy should be tailored following the latest finding.
authors.affiliation: Department of Radiotherapy, Breast Cancer Institute, The Third Hospital of Nanchang, Nanchang 330009, China.
authors.forename: Jingxian
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Breast Surgery, Breast Cancer Institute, The Third Hospital of Nanchang, Nanchang 330009, China.
authors.forename: Pinghua
authors.initials: P
authors.lastname: Hu
authors.affiliation: Department of Breast Surgery, Breast Cancer Institute, The Third Hospital of Nanchang, Nanchang 330009, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Breast Surgery, Breast Cancer Institute, The Third Hospital of Nanchang, Nanchang 330009, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Breast Surgery, Breast Cancer Institute, The Third Hospital of Nanchang, Nanchang 330009, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Cao
keywords: ER/PR; HER2; breast cancer; metastatic lesion; neoadjuvant chemotherapy