Giuseppe Curigliano

Platinum and immunotherapy are now consensus for early triple-negative disease; the open votes have moved to who can safely receive less.

For a fast-moving disease the living guideline, not the 2021 paper, is where European recommendations for triple-negative breast cancer now change; readers should check the website rather than the journal.

Patients with hormone-receptor-positive metastatic breast cancer that has stopped responding to endocrine therapy can be offered trastuzumab deruxtecan as their first chemotherapy-type treatment if the tumour shows any HER2 staining, rather than waiting until after conventional chemotherapy. Whether to use it before or after chemotherapy is now a choice, since overall survival was not shown to differ and the drug carries a risk of lung inflammation.

For TNBC, which is diagnosed young and is the PARP inhibitor-eligible subtype, the guideline makes germline testing part of the diagnostic workup rather than a referral decision.

The evidence behind the stage I de-escalation statement on the triple-negative page: an ordinary haematoxylin and eosin slide identifies a fifth of patients whose outcome without chemotherapy matches treated cohorts. A prospective trial of chemotherapy omission is the missing step.

St Gallen is where de-escalation questions in triple-negative disease (who needs the full KEYNOTE-522 regimen, who can skip adjuvant pembrolizumab) are first put to a vote; the 2023 panel framed intensity and duration as the central problem.

For HER2-positive metastatic breast cancer that has progressed after trastuzumab and a taxane, trastuzumab deruxtecan is now the standard second-line treatment and T-DM1 has moved later in the sequence. The benefit is large enough that ADC design, not just the target, is understood to be what matters. Patients need lung monitoring because of the risk of pneumonitis.

TILs are prognostic without chemotherapy, which is what a de-escalation biomarker has to show before trials omit treatment on its basis.