The first 60 days: Metastatic triple-negative breast cancer
Triple-negative breast cancer that has spread is not curable, but its treatment has been transformed since 2020. By PD-L1 score, first treatment is pembrolizumab with chemotherapy or with sacituzumab govitecan, or datopotamab deruxtecan or sacituzumab govitecan alone; BRCA carriers can take a PARP inhibitor tablet; and trastuzumab deruxtecan reaches the third of tumours with low HER2. Below, week by week, is what OnCo's record of Metastatic triple-negative breast cancer says about the first two months: the order is typical, the timing is yours to ask about. Sections appear only where the record has something to say. Orientation, not medical advice.
What happens now
Staging tests establish exactly what and where the cancer is. Everything else follows from the answers.
Ask which of these were tested and what the results were; see the report reader for what each value means.
These specialties appear in the standard of care for this cancer. In most centres they meet weekly as a tumour board to agree each plan; you can ask when yours was discussed and what was decided.
- Medical oncologistNamed in the standard of care for: First line, combined positive score 10 or more, First line, PD-L1-negative or immunotherapy-ineligible, Germline BRCA carriers, Second line and beyond and 1 more.
- Clinical oncologist (radiotherapy)Named in the standard of care for: Brain metastases.
A second opinion from a centre that treats many similar cases is normal, not rude; the standard of care tells you what to compare it against.
Each row is a setting from the standard of care, in the order it usually arises. Not all will apply to you; your stage and biomarkers decide which do. The guideline grade, where recorded, says how strong the evidence is.
Pembrolizumab with chemotherapy (KEYNOTE-355) or with sacituzumab govitecan (ASCENT-04).
Datopotamab deruxtecan (TROPION-Breast02) or sacituzumab govitecan (ASCENT-03); a taxane or platinum where antibody-drug conjugates are unavailable.
Olaparib (OlympiAD) or talazoparib (EMBRACA) after or instead of first-line chemotherapy; platinum chemotherapy is also more active.
Stereotactic radiosurgery or whole-brain radiotherapy with continued systemic therapy; antibody-drug conjugates have early evidence of intracranial activity.
Whichever TROP2 antibody-drug conjugate has not been used (ASCENT); trastuzumab deruxtecan for HER2-low tumours (DESTINY-Breast04); izalontamab brengitecan where available; eribulin, capecitabine or gemcitabine with carboplatin.
Generated from this cancer's standard of care, biomarkers and open problems. Take the group that matches where you are. To tick, add your own and print, open the one-page appointment sheet.
Newly diagnosed
- What is my exact diagnosis, stage, and grade, and which tests established them?Everything else follows from an accurate stage and subtype.
- Which biomarkers have been tested on my tumour (for example PD-L1 by 22C3 combined positive score, Germline BRCA1 and BRCA2, HER2 immunohistochemistry to identify HER2-low disease, Repeat receptor testing on a metastatic biopsy, TROP2 expression), and what were the results?These results decide eligibility for targeted therapy, immunotherapy, and trials.
- Which subtype is my cancer, and does that change the recommended treatment?Recognised subtypes for this cancer include PD-L1-positive basal-like disease, PD-L1-negative or immunotherapy-ineligible disease, Germline BRCA-mutant metastatic triple-negative disease.
- Is germline (inherited) genetic testing recommended for me or my family?Inherited variants can change treatment and matter for relatives.
First line, combined positive score 10 or more
- For my situation (first line, combined positive score 10 or more), which of the standard options do you recommend and why?Guideline options include: Pembrolizumab with chemotherapy (KEYNOTE-355) or with sacituzumab govitecan (ASCENT-04).
- Am I a candidate for Pembrolizumab, Sacituzumab govitecan, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of KEYNOTE-355 and ASCENT-04 / KEYNOTE-D19 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
First line, PD-L1-negative or immunotherapy-ineligible
- For my situation (first line, pd-l1-negative or immunotherapy-ineligible), which of the standard options do you recommend and why?Guideline options include: Datopotamab deruxtecan (TROPION-Breast02) or sacituzumab govitecan (ASCENT-03); a taxane or platinum where antibody-drug conjugates are unavailable.
- Am I a candidate for Datopotamab deruxtecan, Sacituzumab govitecan, Paclitaxel / nab-paclitaxel or related drugs, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of TROPION-Breast02 and ASCENT-03 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Germline BRCA carriers
- For my situation (germline brca carriers), which of the standard options do you recommend and why?Guideline options include: Olaparib (OlympiAD) or talazoparib (EMBRACA) after or instead of first-line chemotherapy; platinum chemotherapy is also more active.
- Am I a candidate for Olaparib, Talazoparib, Carboplatin, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of OlympiAD and EMBRACA apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Second line and beyond
- For my situation (second line and beyond), which of the standard options do you recommend and why?Guideline options include: Whichever TROP2 antibody-drug conjugate has not been used (ASCENT); trastuzumab deruxtecan for HER2-low tumours (DESTINY-Breast04); izalontamab brengitecan where available; eribulin, capecitabine or gemcitabine with carboplatin.
- Am I a candidate for Sacituzumab govitecan, Trastuzumab deruxtecan, Izalontamab brengitecan or related drugs, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of ASCENT and DESTINY-Breast04 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Brain metastases
- For my situation (brain metastases), which of the standard options do you recommend and why?Guideline options include: Stereotactic radiosurgery or whole-brain radiotherapy with continued systemic therapy; antibody-drug conjugates have early evidence of intracranial activity.
Any stage
- Are there clinical trials I could join, for example of Izalontamab brengitecan, BL-B01D1-307, Sacituzumab tirumotecan, TROPION-Breast05?Trials are how the next standard of care is set; asking early keeps options open.
- Would a second opinion at a high-volume centre change anything, and can you help arrange it?Rare or high-stakes decisions benefit from a centre that treats many similar patients.
- What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Supportive care improves quality of life and helps patients complete treatment.
- I read that “Cross-resistance between antibody-drug conjugates sharing a topoisomerase I payload”. How does that affect my plan?Open problems are where trials and second opinions matter most.
- I read that “No biomarker selects patients for TROP2 drugs”. How does that affect my plan?Open problems are where trials and second opinions matter most.
Trials open now for this cancer in OnCo, largest phase first. Joining a trial is a decision like any other: ask what the comparison arm is, whether a placebo is used, and what happens if you leave. The cancer page searches ClinicalTrials.gov live for more.
Much of what helps in the first weeks is free if you know to ask: testing, helplines, rides and lodging, second opinions, trial travel.
- Metastatic triple-negative breast cancer: the full pageTriple-negative breast cancer that has spread is not curable, but its treatment has been transformed since 2020. By PD-L1 score, first treatment is pembrolizumab with chemotherapy or with sacituzumab govitecan, or datopotamab deruxtecan or sacituzumab govitecan alone; BRCA carriers can take a PARP inhibitor tablet; and trastuzumab deruxtecan reaches the third of tumours with low HER2.
- One-page appointment sheetYour questions, the words you may hear, what to bring, and space for the answers. Print it.
- Treatment sequencingWhich treatment tends to follow which, line by line.
- NavigatorStandard of care for your stage, what you have tried, and trials near you.
- Germline BRCA mutation (gBRCA): An inherited fault in the BRCA1 or BRCA2 gene, present in every cell from birth, that greatly raises the risk of breast, ovarian, prostate and pancreatic cancer and makes those cancers sensitive to PARP inhibitors and platinum.
- Combined positive score (CPS): A PD-L1 score that counts stained tumour cells and immune cells together.
- Brain metastases (intracranial disease): Tumour deposits that have travelled to the brain from a cancer elsewhere, ten times more common than cancers that start in the brain, mostly from lung, breast, melanoma and kidney cancer.
Every term links to the glossary.