MSI-High Metastatic Hormone-Receptor-Positive Breast Cancer Responding to Pembrolizumab
This breast cancer diagnosis at a glance
- Stage at diagnosis
- Stage IV
- Subtype
- Invasive Ductal Carcinoma
- Biomarkers
- ER-positive; PR-positive; HER2-negative; MSI-high; BRCA mutation-negative
- Sex
- female
- Spread to
- bone, para-aortic lymph nodes, brain
- Treatment
- surgery, chemotherapy, endocrine therapy, radiation, targeted therapy and immunotherapy
- Outcome
- Living With Cancer
Treatment course, step by step
- Underwent left nipple-sparing mastectomy with sentinel lymph node biopsy.
- Received 4 courses of docetaxel and cyclophosphamide, followed by tamoxifen.
- After bone metastasis, received radiation plus ovarian suppression, fulvestrant, abemaciclib, and bone-strengthening treatment.
- After further progression, received TS-1.
- Later received pelvic radiation and pembrolizumab for MSI-high disease, continuing pembrolizumab for 1 year before stopping because of appetite loss.
- Continued endocrine therapy afterward.
What happened, in summary
A 40-year-old woman was initially diagnosed with Stage II hormone-receptor-positive, HER2-negative invasive ductal breast cancer. She underwent a nipple-sparing mastectomy and sentinel lymph-node biopsy, followed by 4 courses of docetaxel and cyclophosphamide and then tamoxifen.
Within months, she developed a painful bone metastasis in the right pelvis. Radiation and several endocrine and targeted treatments were tried, but the cancer continued to spread to additional bones and para-aortic lymph nodes. Testing of the breast-cancer tissue showed high microsatellite instability, making pembrolizumab an option.
After 3 pembrolizumab treatments, imaging showed tumor shrinkage and the enlarged para-aortic nodes disappeared. Her pain improved enough to stop opioid medication, and she returned to work. Pembrolizumab continued for 1 year without worsening of the known metastases, then was stopped because of appetite loss. Eight months later she was symptom-free and working while taking an aromatase inhibitor. Asymptomatic brain metastases were also documented, so she continued to live with metastatic breast cancer under follow-up.
Where this story comes from
This is a lay summary of an account first published by PMC / PubMed Central. Read the original in full
How we source and attribute stories Accuracy and limitations
Collections this story belongs to
- Stage 4 Breast Cancer 295 stories
- Hormone Receptor Positive Breast Cancer 41 stories
- Abemaciclib for Breast Cancer 25 stories
These are lay summaries of published cancer stories, for information only. No two cancers behave the same way, and nothing here predicts your own diagnosis or replaces advice from your oncology team. Read the full disclaimer