A study led by Addenbrooke’s Hospital in Cambridge has found that a new treatment approach can significantly improve survival rates among patients with aggressive, inherited breast cancers.
The research, published in Nature Communications, showed that 100% of patients who were treated with chemotherapy followed by the targeted cancer drug olaparib before surgery survived the critical three-year post-surgery period, when there is the greatest risk of relapse or death.
Approximately 55,000 people are diagnosed with breast cancer every year in the UK, and cases linked to faulty copies of the BRCA1 and BRCA2 genes are challenging to treat. Patients typically receive chemotherapy and immunotherapy to shrink their tumour, before undergoing surgery to remove it.
Olaparib tablets, marketed under the brand name Lynparza, are already available on the NHS for certain breast cancer indications and work by inhibiting the PARP enzyme, which helps cells repair damaged DNA. By blocking this enzyme, PARP inhibitors prevent the DNA of cancer cells being repaired, preventing them from growing and spreading.
The Partner trial enrolled patients with early-stage breast cancer and inherited BRCA1 and BRCA2 mutations from 23 NHS sites across the UK and showed that leaving a 48-hour gap between chemotherapy and olaparib improved patient outcomes.
The team noted that this could be due to patients’ bone marrow having time to recover from chemotherapy, while leaving the tumour cells susceptible to olaparib.
Among the 39 patients treated with chemotherapy followed by olaparib, only one relapsed three years post-surgery and 100% survived. This is compared to nine of the 45 patients in the chemotherapy-only cohort relapsing, and an 88% survival rate at the same time point.
Addenbrooke’s consultant and trial lead, Jean Abraham, said: “It is rare to have a 100% survival rate in a study like this and for these aggressive types of cancer. We’re incredibly excited about the potential of this new approach, as it’s crucial that we find a way to treat and hopefully cure patients who are diagnosed with BRCA1 and BRCA2 related cancers.”
The team will now aim to replicate the results in a larger study and confirm that the new approach offers a less toxic treatment for patients compared to the current standard of care.
The research will also aim to demonstrate that the approach is more cost effective, as olaparib-treated patients are currently given the drug post-surgery for 12 months, while patients in the Partner trial took the tablets pre-surgery for 12 weeks.
The trial was funded by AstraZeneca and Cancer Research UK, sponsored by Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge, and supported by the NIHR Cambridge Biomedical Research Centre, the Cancer Research UK Cambridge Centre and Addenbrooke’s Charitable Trust.