Understand your TNBC diagnosis
What 'triple-negative' means, what the standard treatment is and why, what the tests decide, and what is coming next.
- 1CancerTriple-negative breast cancer (TNBC)
A breast cancer that lacks the three receptors (oestrogen, progesterone, HER2) that other breast cancers can be treated through. It was the hardest subtype for decades; since 2020 immunotherapy and ADCs have changed that.
Why here Start here: the whole picture, standard of care by stage, and history.
- 2TermHER2-low and HER2-ultralow
Tumours with a little HER2 (IHC 1+ or 2+ without amplification), or a trace (ultralow), which older HER2 drugs ignored but Enhertu can attack.
Why here Why the HER2 score of 0, 1+, or 2+ matters even in 'HER2-negative' cancer.
- 3TechnologyStandard of careGermline (hereditary) testing
A test of the DNA you were born with, to find inherited risk genes such as BRCA or Lynch syndrome.
Why here Why every TNBC patient is offered inherited-gene testing.
- 4TargetBRCA1 / BRCA2 (HRD)
DNA repair genes. Inheriting a broken copy raises breast and ovarian cancer risk, but tumours that lose them become uniquely vulnerable to PARP inhibitors and platinum.
Why here What a BRCA result changes.
- 5TrialPositiveKEYNOTE-522
The trial that added immunotherapy to pre-surgery chemotherapy for triple-negative breast cancer and, uniquely, improved survival.
Why here The trial behind the pre-surgery chemo-immunotherapy you may be offered.
- 6TermPathologic complete response (pCR)
No invasive cancer left in the breast and lymph nodes when the surgeon removes the tissue after pre-surgery treatment.
Why here What 'complete response' at surgery means for prognosis.
- 7TrialPositiveOlympiA
Showed that a year of a PARP inhibitor after standard treatment improves survival in women with inherited BRCA mutations.
Why here Why some patients take a PARP inhibitor for a year afterwards.
- 8TechnologyStandard of careImmune checkpoint inhibitors
Antibodies that release the brakes on immune cells so they can attack the cancer. They cure a minority of patients across many cancers, something chemotherapy rarely does.
Why here How immunotherapy works and its side effects.
- 9TermCombined positive score (CPS)
A PD-L1 score that counts stained tumour cells and immune cells together.
Why here The PD-L1 score that decides immunotherapy eligibility in metastatic disease.
- 10TrialPositiveTROPION-Breast02
The first trial to show an overall survival benefit for a first-line ADC in triple-negative breast cancer.
Why here The 2026 first-line ADC trial with a survival benefit.
- 11TermTumour-infiltrating lymphocytes (TILs)
Immune cells that have got inside the tumour. More of them means better outcomes in triple-negative breast cancer.
Why here The immune-cell score that may let very small tumours skip chemotherapy.
- 12RoadmapTNBC roadmap: from 'nothing to target' to ADC + immunotherapy first line
How triple-negative breast cancer went from the subtype with no targeted therapy to one with immunotherapy, PARP inhibitors, three ADCs, and a positive bispecific ADC in six years.
Why here Where the field has come from and where it is going.