Case 3: Metastatic Triple-Negative Breast Cancer

Hope Rugo, MD, FASCO: The next case we’re going to talk about is a patient with metastatic triple-negative breast cancer. I think this is really the biggest challenge we all deal with in our treatment of patients with breast cancer because it’s so difficult to treat. And if we don’t see good responses, our options are limited. We’ll talk about some of the areas, based on this case, where we’re making improvements and where we’re going from here. I’m interested in everybody’s approaches.

This patient is a postmenopausal 53-year-old woman who had breast cancer 2.5 years ago. She’s a very active woman. She has 2 teenagers. When she presented, she had a 2.8-cm tumor in the left breast and left axillary node involvement. She had an ultrasound-guided core biopsy that showed a grade 3 invasive ductal cancer that was triple negative, and a fine-needle aspiration of the axillary lymph node showed invasive disease. She had testing per guidelines for BRCA1 and BRCA2 and for multiple other genes, and that was all negative.

She underwent mastectomy followed by immediate reconstruction at another institution and had 2 out of 20 nodes positive as well as a T2 primary lesion. At our institution we would have treated her with neoadjuvant therapy. However, she was treated in another setting.

I think part of what we’re discussing today is the importance of neoadjuvant therapy in HER2-positive and triple-negative disease, in terms of trying to impact outcome. After surgery, she received the standard AC-T [doxorubicin and cyclophosphamide, followed by paclitaxel] regimen—weekly paclitaxel and dose-dense AC.

She had a lot of toxicity with diarrhea and nausea and vomiting, but she got through her chemotherapy and had postmastectomy radiation because of the size of the tumor and the positive nodes. A year and a half later, she presented with a worsening cough and abdominal pain. A CT scan revealed 3 lesions in her left lung and several liver lesions. The results of a biopsy confirmed metastatic triple-negative breast cancer.

She had PD-L1 testing ordered on the biopsy, which showed, based on the VENTANA PD-L1 (SP142) Assay, that her immune cells were positive in the tumor bed for PD-L1.

Transcript edited for clarity.