Breast cancer patients who have a ‘special’ type of immune cell in their tumours have a higher chance of survival than those who do not, new research suggests.

Scientists from the Francis Crick Institute and King’s College London have found a link between a subtype of gamma delta T cells in breast tissue and higher remission rates in patients with triple negative breast cancer.

Gamma delta T cells are specialist immune cells known to have cancer-fighting properties and have been a target for possible immunotherapy treatments.

A subtype of these cells – called V delta 1 T cells – was identified in the tumour samples of some of the patients with triple negative breast cancer.

The scientists found that those with higher numbers of V delta 1 T cells in their tumours were more likely to survive than those with low numbers.

The team say their findings, published in the journal Science Translational Medicine, “open the door to look at new ways we may be able to tackle this devastating disease”.

Gamma delta T cells have previously been identified in the human gut and skin, but the team says this is the first time they have been found in human breast tissue.

Fernanda Kyle-Cezar, a postdoctoral researcher at the School of Immunology and Microbial Sciences, King’s College London, and one of the lead authors of the study, said: “Proving that these special cells are present in human breast tissue is an exciting first.

“We knew from animal model studies that gamma delta cells might play an important role in killing tumours, but this is the first clear evidence that they may do so in human breast cancer.”

Triple negative breast cancer occurs in 15% of cases, with around 7,500 women in the UK being diagnosed each year. It can sometimes be more aggressive than other types of breast cancer and often have a poor prognosis.

In the first part of the study, the team looked at healthy breast tissue from 54 women who underwent mastectomy or reduction.

The researchers were able to detect the gamma delta T cells by tracking their genetic material.

In the second part of the study, the researchers looked for a connection between V delta 1 T cells and survival rates for a group of 11 women with triple negative breast cancer.

They found that six of these patients had relatively high numbers of the cells in their tumours, with five of them going into remission and surviving their cancer.

Study co-author Dr Yin Wu, a clinician at Guy’s and St Thomas’ Hospital and University College Hospital, said: “These findings unlock many more research angles and potential treatments.

“It could mean that in the future we’re able to improve a patient’s chance of survival by either artificially activating more of these cells to fight the tumour cells or we could transfer cells from a donor.”

The research was part-funded by Cancer Research UK and Breast Cancer Now.