A treatment regime combining immunotherapy and chemotherapy can help tune the body's immune system to attack an aggressive type of breast cancer, extending survival by up to 10 months, show results of an immunotherapy trial in Britain.

The research, published in the New England Journal of Medicine, also showed that the combined treatment reduced the risk of death or the progressing of triple-negative breast cancer by up to 40 per cent. "These results are a massive step forward," said author of the trial Peter Schmid, Professor of Cancer Medicine at Queen Mary University of London.

"We are changing how triple-negative breast cancer is treated in proving for the first time that immune therapy has a substantial survival benefit," Schmid, who is also the Clinical Director of the Breast Cancer Centre at St Bartholomew's Hospital in London, added. Triple-negative breast cancer often affects young women, with many people diagnosed in their 40s or 50s. 

The standard treatment is chemotherapy, which most patients quickly develop resistance to. If the disease spreads to other parts of the body, survival is often only 12 to 15 months. The new treatment combines standard weekly chemotherapy with the immunotherapy medication atezolizumab which is given once every two weeks. 

The combination works by chemotherapy 'roughening up' the surface of the cancer, which enables the immune system to better recognise and therefore fight the cancer as a foreign object, the study said. "In a combined treatment approach, we are using chemotherapy to tear away the tumour's 'immune-protective cloak' to expose it as well as enabling people's own immune system to get at it," Schmid explained. 

In the study, the researchers randomly assigned patients with untreated triple-negative breast cancer to receive atezolizumab plus chemotherapy medication nab-paclitaxel or placebo plus nab-paclitaxel. Each group included 451 patients. The participants continued the intervention until disease progression or an unacceptable level of toxic effects occurred. The average follow-up period was more than a year.

The researchers found that combination of immunotherapy and chemotherapy can extend survival of breast cancer patients by up to 10 months. Based on the results of this trial this new treatment is currently under review by health authorities in Britain. "Triple-negative breast cancer is an aggressive form of breast cancer; we have been desperately looking for better treatment options. It is particularly tragic that those affected are often young, with many themselves having young families," Schmid said. "I'm thrilled that by using a combination of immunotherapy and chemotherapy we are able to significantly extend lives compared to the standard treatment of chemotherapy alone."