HER2-Negative Metastatic Breast Cancer: Case 1

CASE 1: HER2-Negative mBC

Jeanne C, 61-year-old postmenopausal white woman from San Angelo, Texas, who works as a copyeditor.

2009: Presented to PCP after finding lump in right breast. Referred to oncologist for standard diagnostic workup.

Diagnosed with stage IIA (T1N1M0) infiltrating ductal adenocarcinoma; 2.0-cm lesion in upper outer quadrant of right breast

Fluorescence in situ hybridization determined HER2-negative/ER+/PR+ tumor

Patient was able to work but felt fatigued and was unable to lift heavy objects

Received lumpectomy and sentinel lymph node biopsy for initial surgery; malignant cells detected in 2 axillary lymph nodes

Patient began TC regimen (Oncotype DX 24): docetaxel 75 mg/m2 IV day 1 + cyclophosphamide 600 mg/m2 IV day 1; every 21 days for 4 cycles with filgrastim support

Chemotherapy was followed by nodal irradiation therapy and whole breast radiation (5x per week for 6 weeks). Started nonsteroidal aromatase inhibitor

Disease-free for almost 5 years after chemotherapy

After almost 5 years, patient reported bone pain and discomfort in upper right quadrant. Mammogram showed new lump in upper right breast.

Medical oncologist ordered bone scan and computed tomography (CT) scan

Patient able to work, but fatigued and working from home 2 days/week

Bone scan and CT scan revealed several potential lesions on spine and long bones

Biopsy and pathology showed metastases consistent with original breast cancer. Patient diagnosed with stage IV cancer

Biopsy confirmed HER2-negative/ER+/PR+ disease. Began denosumab for bone mets

Began treatment with fulvestrant 500 mg IM (2 x 5mL injections on days 1,15, and 29 and every 28 days thereafter)

Patient reports lower back pain before 3rd cycle. Results revealed visceral metastases on liver and on lung.