Doris Ortiz, Medical Technician 2, prepares samples in the specimen set-up area of the  Vanderbilt Clinical Microbiology Lab for patient care, where the fungal meningitis outbreak was first diagnosed, in Nashville, Tennessee

New therapies to stop the deadly progression of breast cancer in its tracks could stem from a fresh study into the disease, researchers believe.

Scientists at the University of Edinburgh said they have discovered a “trigger” that allows breast cancer cells to spread to the lungs.

They found that blocking those signals in mice with breast cancer “greatly reduces” the number of secondary tumours found in the lungs.

The researchers hope their findings may one day translate into new treatments to stop the progression of breast cancer within the human body.

The majority of deaths from breast cancer are said to be caused by the tumour spreading to other parts of the body, with the lungs often among the first organs to be affected.

Researchers at the university’s MRC Centre for Reproductive Health investigated the role that immune cells called macrophages play in helping cells from the original tumour to spread.

Their previous research has shown that breast cancer cells need the support of macrophages to invade the lungs and set up secondary tumours.

The team’s latest research found that macrophages require signalling molecules called chemokines to communicate with breast cancer cells.

But when scientists blocked these signals in mice, they found the number of secondary tumours in the lungs was reduced by up to two-thirds.

In addition, blocking the signals helped to stop the cancer cells getting into the lungs from the blood stream, and hindered those that did get into the lungs from establishing themselves and forming new tumours.

Human cells appear to use the same chemokine signals to communicate with each other, prompting researchers to hope that their findings may translate into new treatments to stop breast cancer spreading to other parts of the body.

Targeting a signalling molecule called CCR1 may result in fewer unwanted side-effects for patients while stopping the spread of breast cancer cells, experts said the results suggest.

Centre director Professor Jeffrey Pollard said: “Our findings open the door to the development of treatments that target the tumour microenvironment, which may stop the deadly progression of breast cancer in its tracks.”