Your ESMO Breast Cancer 2026 preview: What oncologists are buzzing about

As ESMO Breast Cancer 2026 (May 6–8, Berlin) approaches, oncologists are buzzing about new data that could reshape treatment sequencing, especially in antibody-drug conjugate (ADC)-heavy landscapes.

What doctors are buzzing about

ADC sequencing after T-DXd in HER2+ mBC

• SATEEN (LBA4) hosts one of the cleanest post-deruxtecan sequencing questions on the program: sacituzumab govitecan plus trastuzumab in patients with HER2+ metastatic breast cancer after prior T-DXd. The key issue is whether switching ADC target and payload (TROP2/SN-38 after HER2-directed DXd) while maintaining HER2 blockade can retain meaningful activity after T-DXd exposure.^[]

T-DXd moving earlier in HER2+ disease

• LBA1 will put residual cancer burden after neoadjuvant T-DXd–based therapy under the microscope in high-risk HER2+ early breast cancer. Expect discussion on how ADC-containing neoadjuvant strategies may eventually reshape escalation and de-escalation decisions in the curative setting.

Chemo-free and response-adapted HER2+ strategies

• PHERGain-2 and longer-term PHERGain^[] follow-up keep the field focused on a high-stakes de-escalation question: can selected patients with HER2+ early breast cancer avoid conventional chemo without compromising durable disease control? TRAIN-4 adds another layer, pairing chemotherapy-free HER2 blockade with tucatinib and ctDNA monitoring as a translational readout.

SERDs and endocrine resistance moving earlier

• PREcoopERA (LBA2) evaluates giredestrant, an oral SERD, in a window-of-opportunity setting for premenopausal ER+/HER2− early breast cancer. The near-term question is biologic activity and ER pathway suppression, while the broader conversation (also reflected in 2L+ ER+/HER2− metastatic sequencing sessions) is how to manage endocrine resistance after CDK4/6 inhibitor exposure, including ESR1-mutant disease.

Precision medicine beyond the usual subtype lanes

• HER3-DXd/patritumab deruxtecan data across HR+/HER2−, HER2+, and triple-negative metastatic breast cancer will be watched as part of the next wave of cross-subtype ADC development. Separately, LBA3 on the UK Retrospective Genetic Testing Programme shifts the precision-medicine conversation from treatment selection to inherited-risk infrastructure: identifying patients with historic breast or ovarian cancer diagnoses who may now benefit from germline testing and cascade testing for relatives.

Beyond drug development, oncologists are also looking forward to hearing about what’s new in supportive care and survivorship. Expect practice-shaping updates on patient navigation, AI-supported workflows, management of vasomotor symptoms, BMI-associated osteoporosis risk, and bone health surveillance—issues that sit outside systemic therapy selection but can meaningfully affect adherence, toxicity management, quality of life, and long-term outcomes.