A new breast cancer treatment has been found to cut the risk of the disease returning in certain patients by up to quarter.
The results followed a global randomised study, known as “monarchE”, involving 5,637 patients across 38 countries.
The trust described it as “one of the most promising breakthroughs for patients with this type of breast cancer in the last 20 years.”
Patients were given hormone therapy as well as a form of CDK 4/6 inhibitor drug called abemaciclib.
They also followed standard treatments such as chemotherapy, surgery and/or radiotherapy.
Researchers tested whether those who took abemaciclib as well as the standard hormone treatment were less likely to see their cancer return.
Over two years, it found a 25 per cent reduction in recurrence of cancer when abemaciclib was included in the treatment, compared with hormone therapy alone.
Some 11.3 per cent of patients in the control group suffered a relapse of their cancer compared with 7.8 per cent of those in the abemaciclib group, the Royal Marsden said.
Around 70 per cent of breast cancer patients have hormone receptor positive tumours, and a proportion of those have a higher risk of relapse in the first two years, it added.
“Patients with disease that has spread to lymph nodes, a large tumour size at the time of diagnosis, or an increased cellular proliferation (determined by high grade of the tumour, or number of dividing cells) were considered to be at ‘high risk’ of recurrence and recruited to the study,” the trust explained.
Study patient Sarah Ryder, 57, from Dorset, said she “did not feel much hope” after finding out her cancer had spread to 23 lymph nodes when she was referred last year.
She said: “The trial has helped me believe in a future again. I can see my daughter grow up, go off to university next year and maybe have a family of her own one day.”
Professor Stephen Johnston, consultant medical oncologist at the Royal Marsden and professor of breast cancer medicine at the Institute of Cancer Research, said: “This research could potentially save many lives in the future.”
He said: “The monarchE research has given us confidence that we will soon be able to offer our high risk HR+ patients a greater chance of keeping them cancer-free.
“While there have been many advances in other early breast cancer subtypes such as HER2 positive disease, there has been no significant advancements for the large group of patients who have hormone receptor positive breast cancer since the late 1990s when aromatase inhibitors were introduced.
The results of the monarchE study are being presented at the European Society for Medical Oncology Virtual Congress on Sunday evening and simultaneously published in the Journal of Clinical Oncology.
The monarchE trial was funded by Eli Lilly pharmaceutical.