• Claudin-low breast cancer: Claudin-low breast cancers have lost the claudin proteins that hold epithelial cells together and have taken on the features of migrating, stem-like cells.
• Lumpectomy (breast-conserving surgery): Removing only the tumour with a rim of normal breast, keeping the breast; almost always followed by radiotherapy.
• Grade: How abnormal the cancer cells look under the microscope, from grade 1 (close to normal, slow) to grade 3 or 4 (wildly abnormal, fast).
• Mastectomy: Removing the whole breast, either for cancer or preventively in BRCA1/2 carriers, where bilateral risk-reducing mastectomy cuts breast cancer risk by 90% or more.

Biomarker results to ask for: Triple-negative receptor status (70.3 percent), Mesenchymal or squamous component on histology (with cytokeratin and p63 immunostains), EGFR amplification, PIK3CA and TP53 mutations (research).

Bring copies of scan reports, pathology and blood results, and a list of every medicine and supplement.

• Early disease: Surgery and radiotherapy, with chemotherapy as for triple-negative disease of no special type; chemotherapy and radiotherapy were associated with better survival in the national database, and axillary dissection was not. Low-grade adenosquamous and fibromatosis-like forms are treated by surgery alone in the European working group's consensus. (Mastectomy, Lumpectomy (breast-conserving surgery), Sentinel lymph node biopsy, Carboplatin, Paclitaxel / nab-paclitaxel)
• Advanced disease: As for metastatic triple-negative disease (pembrolizumab where PD-L1 positive, TROP2 ADCs); response to chemotherapy is poorer than in other triple-negative cancers. (Pembrolizumab, Sacituzumab govitecan)

From the standard of care recorded for this cancer; which apply depends on your stage and biomarkers. Ask which the team recommends and why.