What is TNBC and why is it distinct from other cancers?

• How common: roughly 1 in 10 breast cancers (about 10–20%).
• What “triple-negative” means: Your test results came back as ER-, PR-, and HER2-
• Who can be affected: anyone; more often seen in younger people, Black women, and some with BRCA1 mutations.
• Behavior: can be faster-growing early on; if it doesn’t recur in the first 3–5 years, risk generally drops substantially afterward.
• Chemo sensitivity: many TNBCs respond strongly to chemotherapy; some shrink quickly.
• pCR (pathologic complete response): after chemo-first, no invasive cancer found in breast and sampled nodes at surgery—linked with better outlook.
• Clinical trials: available at multiple stages; often add options without removing standard care.

• ER- and PR-negative: The cancer does not express estrogen or progesterone receptors, so hormone-blocking therapies don’t help.
• HER2-negative: The HER2 gene is present in everyone, but some cancers make too much HER2 (called overexpression) and can be treated with HER2-targeted drugs. TNBC has a normal HER2 result (not overexpressed).

Together (ER-negative, PR-negative, and HER2-negative) define triple-negative.

• ER/PR/HER2: receptors tested on your tumor; “triple-negative” means all three are negative.
• Grade (differentiation): how fast-growing the cancer looks under the microscope.
• Neoadjuvant / Adjuvant: chemo before / after surgery.
• pCR: no invasive cancer found at surgery after chemo-first—good sign

See the Glossary of Terms below.

A lump may may be felt by you or your clinician, or seen on a mammogram, ultrasound, or MRI. Diagnosis is confirmed with a core needle biopsy. Your pathology report lists ER/PR/HER2, grade, and other details your team uses to stage the cancer and plan treatment.

Read more here: TrNBC Pathology & Reports →

• Bring a support person to appointments (or record notes).
• Collect your reports: imaging, biopsy, and lab results.
• Bring CD's of all your imaging: Mammograms, ultrasounds and MRI's.
• Ask about timing: chemo-first vs surgery-first for your case.
• Ask about eligibility for immunotherapy or a clinical trial. (Read more about diagnosis and clinical trials) 
• Write down questions—use our Appointment Checklist (below)

• Chemotherapy – Given before surgery (neoadjuvant) to shrink tumors and gauge response, or after (adjuvant) to lower the chance of return.
• Surgery – Lumpectomy (breast-conserving) or mastectomy; usually with sentinel lymph node biopsy. Chemo-first may open the door to breast conservation or less node surgery.
• Radiation – Lowers the chance of cancer returning in the breast/chest wall or nearby nodes; modern techniques spare heart and lungs.
• Newer options – Immunotherapy and ADCs in specific settings based on tumor testing and stage.
• Reconstruction/Oncoplastic – Options after mastectomy or to optimize shape with breast-conserving surgery.

Read more here: Treatment Options → 

• “Trials are only for advanced cancer.” Many trials enroll people with early-stage cancers.
• “If I join a trial, I might get only a placebo.” In cancer trials, placebos are rarely used alone; if present, they’re typically given with standard treatment.
• “Chemo before surgery is always better.” Timing is personalized—both approaches can be curative; your team recommends what best fits your situation.