Singapore Study Finds Node-Negative Breast Cancer Can Carry Recurrence Risk Matching Node-Positive Cases

Of the nearly 3,000 breast cancer patients whose records were examined in a new Singapore study, one group stands out: women whose cancer had not reached the lymph nodes, but who did no better than some whose cancer had. Among higher-risk patients with hormone receptor-positive, HER2-negative early breast cancer and no lymph-node involvement, 16.7% had a recurrence or died within seven years. That is roughly one in six.

The finding comes from the RACES study, short for Real-World Assessment of Treatment Patterns and Outcomes During the Pre-Adjuvant CDK4/6 Inhibitor Era of HR+/HER2− Early Breast Cancer in Singapore. It was presented at the European Society for Medical Oncology Congress (ESMO 2026) in Madrid. The work was a research collaboration between Novartis Singapore and the National Cancer Centre Singapore (NCCS). NCCS served as regulatory sponsor, and Novartis provided the funding.

The researchers drew on data from 2,987 patients in Singapore's Joint Breast Cancer Registry, all diagnosed between 2010 and 2017, with a median follow-up of more than eight years. The study was retrospective. It looked at patient characteristics, how patients were treated and their long-term outcomes, in the period before adjuvant CDK4/6 inhibitors were introduced. The HR+/HER2− subtype is the most common form of breast cancer, accounting for around 70% of cases.

The comparison is what gives the result its weight. The 16.7% seven-year rate among higher-risk node-negative patients closely matched the 16.4% seen in patients whose cancer had spread to one to three lymph nodes. Lower-risk node-negative patients fared better, with a rate of 9.4%. The higher-risk node-negative patients were defined by tumour or disease characteristics linked to a greater likelihood of recurrence, despite the absence of nodal spread. The result challenges the assumption that node-negative early breast cancer is always low risk, and suggests lymph-node status alone may not capture the full picture.

The study also points to Ki67, a marker measured through a test on tumour tissue that shows how quickly cancer cells are dividing and gives doctors a sense of how aggressive a cancer may be. According to the study, such testing may help identify node-negative patients at higher risk of recurrence, and support earlier, better-informed discussions about treatment after surgery.

Dr Elaine Lim, the study's Principal Investigator and lead author, and a Senior Consultant in the Division of Medical Oncology at NCCS, placed the findings in the context of East Asian women. They tend to be diagnosed a decade earlier than their Caucasian counterparts, she said, often while balancing careers, child-raising and the care of ageing parents. She said the results reinforce the need to look beyond lymph-node involvement when assessing recurrence risk, so clinicians can talk early with patients about their individual risk and the treatment options available.

Dr Esdy Rozali, study co-lead and co-author from Medical Affairs at Novartis Singapore, described RACES as adding Singapore-specific evidence. Some patients without lymph-node involvement, he said, can face outcomes similar to those with cancer in one to three nodes, and the long-term data can help clinicians identify higher-risk patients more comprehensively.

The study's design carries limits. It is retrospective and covers the era before adjuvant CDK4/6 inhibitors, so its findings will need validation in today's treatment settings.