Selecting patients for adjuvant ribociclib in early ER+/HER2− breast cancer

In this video, Babette Salaets, Clinical Fellow Gynaecology, presents research on the importance of careful patient selection for adjuvant ribociclib in early-stage ER+/HER2− breast cancer. 

Following the results of the NATALEE trial, adjuvant ribociclib was approved for a broader group of patients compared with earlier CDK4/6 inhibitor trials, including all node-positive patients and selected node-negative patients with high-risk features. However, this expanded eligibility raises the question of whether some patients with more favourable tumour biology already have excellent outcomes with endocrine therapy alone and may therefore derive limited additional benefit from three years of ribociclib. 

To explore this, a single-centre retrospective analysis was performed of patients treated between 2000 and 2023 who would have met the NATALEE eligibility criteria. Within this population, a predefined “lower-risk” subgroup was identified: pT0–2N1 tumours with grade 1–2 disease. Outcomes were compared between the overall eligible cohort and this lower-risk subgroup using invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). 

The results showed that lower-risk NATALEE-eligible patients had more favourable 4-year IDFS and DDFS, supporting the idea that not all eligible patients may need additional CDK4/6 inhibitor therapy. These findings highlight the need to balance potential benefit against toxicity and support further research into better tools to refine patient selection in clinical practice.