'Transformational' new drug could stop breast cancer tumours before they grow, trial finds

A new drug could stop some breast cancer tumours from using hormones to grow, a trial has found.

Results from the Serena-6 trial, carried out with the Institute of Cancer Research in London, suggest that using camizestrant could help patients stay well longer and delay the need for chemotherapy. According to Cancer Research UK, the drug works by blocking oestrogen from getting into the breast cancer cell, which researchers hope can then stop or slow the growth of cancer.

Breast cancer patients given the drug in the trial reduced their chances of the disease progressing by 52% compared to standard therapies. Professor Kristian Helin, chief executive of the Institute of Cancer Research, said the results "represent more than a clinical milestone, they represent a transformational shift in how we approach precision medicine".

Co-principal investigator Professor Nick Turner also called the development of the drug "a pivotal moment in breast cancer care". The study, funded by AstraZeneca, looked at patients with hormone-positive, HER2-negative breast cancer - about 70% of cases.

More than 3,000 patients from 23 countries took part in phase three of the trial, which saw doctors use blood tests to detect changes in the cancer's DNA to see which treatments were ineffective. For those taking camizestrant, their cancer stabilised for around 16 months on average, compared with about nine months for other treatments.

However, 1% of patients taking the new drug stopped taking it because of side effects. Read more:New drug combination could help cancer patientsTest uses AI to detect cancer at earliest stage yetHow aspirin could stop some cancers spreading Further results from the Serena-6 trial will be presented at the American Society of Clinical Oncology annual meeting in Chicago on Sunday.

Cancer Research UK reports that breast cancer is the most common type of the disease, with around 56,400 women and around 390 men diagnosed in the UK each year. The trial was also the first worldwide study to show that using blood tests to find early signs of cancer resistance to treatment helps patients.

Dr Catherine Elliott, director of research at Cancer Research UK, praised the breakthrough as a "clear example of how blood tests are starting to transform cancer treatment". "By tracking tiny traces of tumour DNA in the blood, researchers were able to spot early signs of treatment resistance and switch therapies before cancer had a chance to grow," she added.

"It shows how circulating tumour DNA, or ctDNA, could help doctors make smarter, more timely treatment decisions. "This approach could become an important part of how we personalise care for people with advanced breast cancer.".