Women with inherited breast cancer, triggered by the BRCA1 or BRCA2 genes, have a better chance of surviving after successful trials of a drug that reduces the chance that the cancer will come back after treatment.
A major trial by academic researchers to see if olaparib can prevent recurrence was stopped early, after two and a half years instead of the expected 10 years, when the drug’s benefits became apparent.
The results, published in the New England Journal of Medicine and presented online at the American Society of Clinical Oncology conference, showed that it reduced the relative risk of invasive recurrence, second cancers or death by more than 40%.
In absolute terms, 85.9% of the women who received olaparib in pill form for one year after the end of their treatment remained alive without recurrence of cancer for three years, compared with 77.1% who received a placebo . The difference was similar for metastatic disease, which are cancers that occur in other parts of the body: 87.5% with olaparib and 80.4% with placebo.
Of the 921 patients who received olaparib, 106 had an invasive cancer recurrence or died within three years, compared with 178 (of 915) patients who received a placebo.
“In terms of curative therapy trials, this is a really important result,” said Professor Andrew Tutt of the London Cancer Research Institute, who led the international trial.
For every 100 women treated, he meant, he said, “nine additional women, say eight or nine women, who are alive and well, with no evidence of a recurrence of breast cancer or the development of any other cancer.”
Until this trial, there was nothing that could help women with inherited genes for breast cancer, who are often young and have the most severe forms of cancer, who feared their cancer would come back.
“Every year thousands of women in the UK are diagnosed with hereditary breast cancer caused by an altered BRCA gene,” said Dr Simon Vincent, director of research for the charity Breast Cancer Now. “Ending active hospital treatment can be an incredibly difficult time, and many women call our helpline to share their anxiety and fears that their breast cancer will return. Therefore, it is vitally important to find new effective ways to prevent recurrence.
“It is extremely exciting that this groundbreaking study can pave the way for a specific treatment for women with high-risk HER2-negative primary breast cancer with altered BRCA genes, preventing recurrence and potentially helping to prevent women from dying from this devastating disease. Olaparib must now be shipped immediately for licensing and then evaluated for use on the NHS, so that women with this type of breast cancer start to benefit from this new discovery as soon as possible. “
Olaparib works by stopping cancer cells from repairing their DNA by inhibiting a molecule called PARP, which causes cancer cells to die. It works particularly well for patients with faulty versions of the BRCA1 or BRCA2 genes, which are normally involved in another system for repairing DNA. In the trial, significant side effects were reported to be relatively rare.
The drug is already licensed for use in the treatment of genetic forms of breast, ovarian, prostate and pancreatic cancer, although it is expensive and not yet available on the NHS. The researchers hope their study will help speed up a license for olaparib that will allow all women who have recovered from inherited breast cancer to take it.
George is Digismak’s reported cum editor with 13 years of experience in Journalism