Stage IV HER2-Positive Breast Cancer: Stephani's Survivor Story
This breast cancer diagnosis at a glance
- Stage at diagnosis
- Stage IV
- Biomarkers
- HER2-targeted treatments reported; no inherited cancer gene mutation found.
- Sex
- Female
- Spread to
- Bone; liver; brain
- Treatment
- chemotherapy, targeted therapy and surgery
- Outcome
- Cancer-Free / NED
Treatment course, step by step
- March 2019 Stage IV metastatic breast cancer with spread to bones and liver
- 6 rounds of chemotherapy
- 1 year of trastuzumab/Herceptin plus pertuzumab/Perjeta
- June 2021 brain tumor found after dizziness
- brain surgery within 1 week
- trastuzumab deruxtecan/Enhertu, initially difficult to tolerate
- current trastuzumab plus tucatinib/Tukysa and capecitabine; no evidence of disease since July 2021.
What happened, in summary
Stephani St. Cyr felt a long lump under her right arm while watching a movie at home. Her primary doctor suspected a cyst but referred her to a specialist. The breast cancer doctor immediately suspected cancer, and biopsy confirmed it. Further tests showed the cancer had already spread to her bones and liver, and in March 2019 Stephani was diagnosed with Stage IV metastatic breast cancer. She began treatment with 6 rounds of chemotherapy, followed by 1 year of trastuzumab/Herceptin and pertuzumab/Perjeta. In June 2021, dizziness led to more testing, and doctors found a brain tumor. Surgery was scheduled quickly, and the tumor was removed within a week. Her treatment was changed to trastuzumab deruxtecan/Enhertu, which initially made her sick before her body adjusted. Later, she moved to trastuzumab plus tucatinib/Tukysa and capecitabine. As of March 2025, Stephani had remained without evidence of disease since July 2021. Faith, advocacy, family, and service became central to how she lived with metastatic breast cancer. She also used her experience to encourage self-education, genetic testing when appropriate, and better access to breast cancer information in Black and Brown communities.
Where this story comes from
This is a lay summary of an account first published by Living Beyond Breast Cancer. Read the original in full
How we source and attribute stories Accuracy and limitations
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