Kefah Mokbel, Chair of Breast Cancer Surgery at London Breast Institute and Honorary Professor of Medicine at Cardiff University School of Medicine, shared on LinkedIn:
“New expert consensus: how to sequence radiotherapy with ADCs, immunotherapy and CDK4/6 inhibitors in breast cancer – and why it matters most where resources are limited
A multidisciplinary AROME/Moroccan Medical Oncology panel has just published a modality-by-modality safety matrix for combining RT with the drugs that have transformed breast cancer over the last five years – trastuzumab deruxtecan, sacituzumab govitecan, T-DM1, checkpoint inhibitors, and CDK4/6 inhibitors (JCO Global Oncology, 2026).
The headline finding clinicians need to internalise: T-DM1 + stereotactic radiosurgery for brain metastases is not interchangeable with T-DXd + SRS. Reported radionecrosis rates reach up to 30% with T-DM1 around SRS versus 5-10% with SRS alone – one series put clinically significant radionecrosis at 39.1% vs 4.5%. T-DXd, by contrast, appears ‘safe’ with SRS in this consensus. That is a meaningful distinction when choosing sequencing for HER2-positive patients with brain disease.
Elsewhere the pattern is reassuring:
- ADCs with whole-breast irradiation – generally safe, watch skin toxicity.
- Checkpoint inhibitors across WBI, SBRT and SRS – no consistent excess-toxicity signal.
- CDK4/6 inhibitors – safe with WBI and stereotactic techniques, caution with visceral targets and haematologic overlap.
- Sacituzumab govitecan with SRS – insufficient evidence; sequential therapy preferred.
What I find most useful here isn’t just the safety grading – it’s the resource-stratified implementation checklist (Table 2), which translates the same safety categories into concrete steps for basic, limited, and enhanced RT settings. That’s a genuinely practical contribution for units without routine IGRT or breath-hold capability, not just an academic exercise.
Almost everything here rests on retrospective data. The panel is explicit about that, and rightly calls for prospective validation – but in the absence of randomised evidence, this is the most granular, agent-specific guidance available for daily decision-making.
Reference: Debbi K, Bellefkih FZ, Bennassi A, et al. Concurrent New Systemic Therapies and Radiation Therapy in Breast Cancer: Current Evidence, Future Challenges, and Expert Practice Recommendations for Low- and Middle-Income Countries. JCO Global Oncology.”
Title: Concurrent New Systemic Therapies and Radiation Therapy in Breast Cancer: Current Evidence, Future Challenges, and Expert Practice Recommendations for Low- and Middle-Income Countries
Authors: Kamel Debbi, Fatima Zahra Bellefkih, Alexander Bennassi, Meriem El Bachiri, Salma El Mouhtadi, Youssef Bensouda, Lahcene Belaidi, Kawtar El Hassani, Sami Frikha, Nisrine El Hayel, Dusanka Tešanović, Pelagia G. Tsoutsou, Joseph Gligorov, Yazid Belkacemi
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