UK breast cancer treatment regimen shows 100% three-year survival for BRCA patients: study

University of Cambridge-led trial shows significant improvement in outcomes for inherited, aggressive forms of breast cancer

A novel treatment strategy for aggressive, inherited breast cancers has resulted in a 100% three-year survival rate among participants, according to research conducted by Cambridge researchers, introduces a refined sequencing of chemotherapy and targeted therapy prior to surgery – offering the most effective approach to date for early-stage breast cancers linked to BRCA1 and BRCA2 gene mutations.

The Partner trial, led by Addenbrooke’s Hospital and the University of Cambridge, involved 84 patients across 23 NHS sites in the UK. It tested a combination of standard chemotherapy followed by a 12-week course of the targeted cancer drug olaparib – administered before surgery. Olaparib, already available on the NHS, is a PARP inhibitor taken orally and known for targeting BRCA-mutated cells.

A critical component of the new approach was the introduction of a 48-hour interval between chemotherapy and olaparib administration, allowing patients’ bone marrow to recover while tumour cells remain vulnerable. Of the 39 patients who received the combined treatment, only one relapsed after three years, with all patients surviving the critical post-operative period.

In contrast, among the 45 patients in the control group – who received only chemotherapy – nine experienced a relapse and six died, yielding an 88% survival rate at three years.

“It is rare to see a 100% survival rate in a study of this kind, especially for aggressive cancer types,” said Professor Jean Abraham, the trial’s chief investigator and a consultant at Addenbrooke’s Hospital.

“This new approach has the potential to become a transformative option for patients with BRCA-related cancers,” she added.

The BRCA1 and BRCA2 genes became widely recognised following actress Angelina Jolie’s decision in 2013 to undergo a preventative double mastectomy due to her BRCA1 status. Faulty versions of these genes significantly increase the risk of breast, ovarian, and other cancers, and the associated tumours are typically more aggressive and resistant to standard treatments.

One of the study’s participants, Jackie Van Bochoven, 59, from South Cambridgeshire, was diagnosed in early 2019 with an aggressive tumour. “When I had the diagnosis, I was completely shocked and numb,” she said.

“Six years on, I’m well and cancer-free. I’m back at work, enjoying life, and spending time with my family. Every day is a bonus.”

Beyond its clinical impact, the Partner approach may also reduce treatment costs for the NHS. Patients currently receiving olaparib post-surgery are prescribed a 12-month course, while the new regimen requires only 12 weeks of pre-surgical use.

The trial’s success also reflects close collaboration between the NHS, academic institutions, and industry, including AstraZeneca, which manufactures olaparib. The 48-hour treatment gap strategy originated from a discussion between Professor Abraham and Dr Mark O’Connor, chief scientist in Early Oncology R\&D at AstraZeneca.

“This study underscores the power of innovative science to reshape clinical trial design and improve patient outcomes,” said Dr O’Connor.

“While these results need to be validated in a larger cohort, they offer great promise for patients with urgent unmet clinical needs,” he added.

“This is a striking example of how existing treatments can be deployed more effectively to give patients with inherited breast cancers more time with their loved ones. Further research is now needed to confirm safety and scalability,” said Michelle Mitchell, Chief Executive of Cancer Research UK, welcoming the findings.

The next phase of the research will assess whether the Partner approach can be replicated in a larger patient group, with the aim of confirming both its clinical efficacy and its potential to reduce toxicity and cost relative to the current standard of care.

The trial was jointly sponsored by Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge, with funding from Cancer Research UK and AstraZeneca. Additional support was provided by the NIHR Cambridge Biomedical Research Centre, the Cancer Research UK Cambridge Centre, and Addenbrooke’s Charitable Trust.

For further reading please visit: 10.1038/s41467-025-59151-0