HER2-Negative Metastatic Breast Cancer: Case 2

CASE 2: HER2-Negative Chemotherapy-Resistant mBC

Kim W, 53-year-old postmenopausal woman of Asian decent from Morristown, New Jersey, who worked as an accountant.

2013: Presented to PCP after finding a lump in right breast. Referred to oncologist for standard diagnostic workup.

Diagnosed with infiltrating ductal adenocarcinoma; 5.5-cm lesion in lower outer quadrant of right breast and palpable ipsilateral axillary nodes, which were FNA+ for adenocarcinoma

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

Patient was able to work and carry out daily activities (KPS score 94)

Bone scan and chest diagnostic CT revealed no metastases

Neoadjuvant therapy begun with dose-dense AC: doxorubicin 60 mg/m2 IV q2 weeks followed by weekly paclitaxel 80 mg/m2 x 12

Patient underwent breast-conserving therapy (malignant cells in 7 axillary lymph nodes)

Surgery followed by chest wall and regional lymph node radiation therapy (5x/week for 6 weeks). Started nonsteroidal aromatase inhibitor.

5 months after adjuvant chemotherapy treatment, patient complained of bone pain.

Patient was unable to work, but could carry out self care and some home upkeep

Bone scan and CT scan revealed several metastases: 2 lesions on right leg bone measuring 2-3 cm, 2 lesions on liver measuring 2-3 cm; 1 lesion on lung measuring 2-3 cm

Patient identified as potentially resistant to taxane (having progressed within 12 months of last adjuvant therapy)

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

Histology confirmed HER2-negative/ER+/PR+ disease. Began therapy with denosumab for bone metastases

Also received Xeloda 1000 mg/m2 PO BID day 1-14

Also received Xeloda 1000 mg/m2 PO BID day 1-14