Aspirin could be part of a new treatment for an aggressive form of breast cancer, if trials are successful.
The cheap and widely-available drug is being tested to see if it can make tumours more sensitive to immunotherapy for patients with triple negative breast cancer.
The trial, funded by the Breast Cancer Now Catalyst Programme, will test the drug avelumab both with and without aspirin before patients have surgery and chemotherapy.
Successful results could lead to further clinical trials of aspirin and avelumab for incurable secondary triple negative breast cancer, which affects around 8,000 women in the UK each year.
The less common but often more aggressive type of breast cancer disproportionately affects young women and black women.
Dr Anne Armstrong, a consultant medical oncologist from the Christie NHS Foundation Trust in Manchester, will lead the study.
She said: “Our earlier research has suggested that aspirin can make certain types of immunotherapy more effective by preventing the cancer from making substances that weaken the immune response.
“Anti-inflammatory drugs like aspirin could hold the key to increasing the effectiveness of immunotherapy when used at the same time.
“Trialling the use of a drug like aspirin is exciting because it is so widely available and inexpensive to produce.
“We hope our trial will show that, when combined with immunotherapy, aspirin can enhance its effects and may ultimately provide a safe new way to treat breast cancer.”
Dr Simon Vincent, director of research, support and influencing at Breast Cancer Now, said: “The 8,000 women diagnosed with triple negative breast cancer in the UK each year face the frightening reality of limited treatment options – we urgently need to address this.
“Research has already suggested aspirin could improve outcomes for many cancer patients and we hope that Dr Armstrong’s trial will show the same to be true for patients with triple negative breast cancer, so that we can prevent more lives being lost to this devastating disease.”
Breast Cancer Now said pharmaceutical company Pfizer had provided funding through an independent medical research grant, while also giving the researchers access to several Pfizer medicines.