A new Singapore study found that around one in six (16.7%) higher-risk patients with hormone receptor-positive (HR+), HER2-negative early breast cancer whose cancer had not spread to the lymph nodes experienced recurrence or death within seven years. These “high-risk node-negative” patients had tumour or disease characteristics associated with a higher likelihood of recurrence despite having no lymph-node involvement. Their outcomes were comparable to those of patients whose cancer had spread to one to three lymph nodes, challenging the assumption that node-negative early breast cancer is always low risk.
Presented at the European Society for Medical Oncology Congress (ESMO 2026) in Madrid, the Real-World Assessment of Treatment Patterns and Outcomes During the Pre-Adjuvant CDK4/6 Inhibitor Era of HR+/HER2− Early Breast Cancer in Singapore (RACES) study was conducted through a research collaboration between Novartis Singapore and the National Cancer Centre Singapore (NCCS).
The retrospective study analysed real-world data from 2,987 patients in Singapore’s Joint Breast Cancer Registry who were diagnosed between 2010 and 2017, with a median follow-up of more than eight years. It examined patient characteristics, treatment patterns and long-term outcomes before adjuvant CDK4/6 inhibitors were introduced. NCCS was the regulatory sponsor, with funding from Novartis.
HR+/HER2− is the most common subtype of breast cancer, accounting for around 70% of cases.
The seven-year rate of recurrence or death among higher-risk patients without lymph-node spread was 16.7%, closely matching the 16.4% observed among patients whose cancer had spread to one to three lymph nodes. By comparison, the rate was 9.4% among lower-risk patients without lymph-node spread. The findings show that lymph-node status alone may not fully capture recurrence risk and reinforce the importance of discussing risk and treatment options early.
“Breast cancer has a particularly significant impact on East Asian women, who tend to be diagnosed a decade earlier than their Caucasian counterparts, often when they are balancing multiple roles with careers, child-raising and responsibilities caring for ageing parents. RACES’ findings reinforce the need to look beyond lymph-node involvement when assessing recurrence risk, so that clinicians have early conversations with patients about their individual risk and discuss available treatment options to enable them to make informed care decisions,” said Dr Elaine Lim, the study’s Principal Investigator and lead author, and Senior Consultant, Division of Medical Oncology at the National Cancer Centre Singapore.
RACES’ findings also highlight the potential role of Ki67, a marker measured through a test on tumour tissue that shows how quickly cancer cells are dividing, giving doctors a sense of how aggressive the cancer may be. The study suggests that such testing may help identify patients with node-negative early breast cancer who are at higher risk of recurrence, supporting early and more informed discussions about treatment after surgery.
Study co-lead and co-author Dr Esdy Rozali, Medical Affairs, Novartis Singapore, said: “RACES adds important Singapore-specific evidence by showing that some patients without lymph-node involvement can face outcomes similar to those with cancer in one to three lymph nodes. Its long-term data can help clinicians look beyond nodal status, identify higher-risk patients more comprehensively and support earlier, more informed conversations about recurrence risk and treatment after surgery.”
