London, UK (Scicasts) — Scientists have developed a new test that can pick out women at high risk of relapsing from breast cancer within 10 years of diagnosis.

Their study looked for immune cell ‘hotspots’ in and around tumours, and found that women who had a high number of hotspots were more likely to relapse than those with lower numbers.

The new test could help more accurately assess the risk of cancer returning in individual patients, and offer them monitoring or preventative treatment.

Scientists at The Institute of Cancer Research, London, analyzed tissue samples from 1,178 women with the most common form of breast cancer - oestrogen receptor positive breast cancer.

The team created a new, fully automated computer tool to analyze the samples, which were taken as part of a clinical trial at The Royal Marsden NHS Foundation Trust and other hospitals in the UK, comparing two hormone therapies that can help stop cancer recurring after surgery.

The researchers found that when immune cells clustered together in hotspots, the chance of relapse within 10 years of starting treatment was 25% higher than when immune cells were evenly dispersed.

The chance of cancer returning within five years was 23% higher in women with immune cell hotspots.

The researchers previously looked at tumour samples from oestrogen receptor-negative breast cancer, and found here that clustering of immune cells had the opposite effect, with hotspots linked to a lower chance of relapse.

Finding new immunotherapy drug targets

The study was published in the Journal of the National Cancer Institute Aug. 4, and was funded by the NIHR Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and the ICR, with support from Breast Cancer Now, Cancer Research UK, and Wellcome.

Once the new test is validated, it could be used to help predict the risk of cancer relapse, and to make decisions about the right course of treatment.

The effect of immune hotspots on the chance of relapse could be linked to how the immune system is working in these cancers.

Better understanding of the immune system in breast cancer could in future help unpick why certain immunotherapies work in some patients but not others, and lead to finding new immunotherapy drug targets.

Dr. Yinyin Yuan, Team Leader in Computational Pathology at the ICR, said:

“We have developed a new, automated computer tool that makes an assessment of the risk of relapse based on how cells are organized spatially, and whether or not immune cells are clustered together in the tumour.

“In the most common form of breast cancer, oestrogen receptor positive, the presence of hotspots of immune cells clustered together in the tumour was strongly linked to an increased risk of relapse after hormone treatment.

“Larger studies are needed before an immune hotspot test could come to the clinic, but in future such a test could pick out patients at highest risk of their cancer returning. It might also be possible to predict which patients would respond to immunotherapy.

“The samples used in our study already form part of routine clinical practice, which means that implementing an immune hotspot test would be relatively easy and cost-effective.”

Article adapted from a ICR news release.

Publication: Relevance of Spatial Heterogeneity of Immune Infiltration for Predicting Risk of Recurrence After Endocrine Therapy of ER+ Breast Cancer. Andreas Heindl et al. Journal of the National Cancer Institute (2017): Click here to view.