Researchers have developed a DNA test that can identify breast cancer patients who would benefit from chemotherapy versus those who can safely forgo the treatment, potentially sparing millions from unnecessary treatment based on recent trial findings.
The global research demonstrated that over two-thirds of participants could avoid chemotherapy side effects by receiving hormone therapy instead.
Potential chemotherapy side effects include fatigue, nausea, hair loss, compromised immunity and fertility concerns.
Conducted under the leadership of University College London (UCL), the study included over 4,000 recently diagnosed breast cancer patients aged 40 and above from the UK, Norway, Sweden, Australia, New Zealand, and Thailand.
Researchers utilized the Prosigna gene test to assess the activity of 50 genes related to breast cancer progression and determine a patient’s likelihood of disease recurrence.
Individuals with low-risk scores – comprising two-thirds of participants – did not receive chemotherapy. Their five-year survival rate stood at 93.7%, compared to 94.9% among patients who underwent chemotherapy as part of their treatment plan.
Surgical removal of tumors remains the standard primary treatment for breast cancer, with chemotherapy frequently recommended afterward to reduce the risk of recurrence.
Chemotherapy is also commonly provided to individuals with early-stage breast cancer that has metastasized to nearby lymph nodes.
According to UCL, medical professionals have expressed concerns that chemotherapy offers minimal advantages for patients with the most prevalent form of breast cancer.
The university estimates that annually, over 5,000 NHS patients could be spared chemotherapy through implementation of this testing approach.
Karen Bonham of Cardiff participated in the trial, describing the outcome as an “immense relief” comparable to “Christmas”. The 64-year-old avoided chemotherapy through the Prosigna test and instead received radiotherapy and hormone therapy over an eight-year period.
A cancer diagnosis and treatment process can be profoundly distressing,” she shared. “It thrusts you into a realm of uncertainty where life priorities shift dramatically, with survival becoming the paramount concern.”
Research outcomes will be presented at the world’s largest cancer conference, the American Society of Clinical Oncology’s annual gathering in Chicago, this Saturday.
Prominent cancer specialist Professor David Miles characterized the findings as “practice-changing”. “We can now confidently determine that numerous patients will derive no benefit from chemotherapy, eliminating the necessity for them to undergo this treatment,” he stated during BBC’s Newshour broadcast.
He further explained that the test enables physicians to “confidently identify a substantial group of women who will not experience benefits and should not endure the associated unpleasantness without potential gain.” Historically, we administered chemotherapy to 100 women to benefit just 10, while 90 received no actual benefit,” he noted. Tanya Hutson, diagnosed with breast cancer in 2022 and treated with chemotherapy, described the new DNA test as “absolutely amazing”. “This demonstrates the impact when resources are allocated to research,” she remarked, noting that chemotherapy had been “brutal”. “For all those individuals undergoing unnecessary treatment – this represents a transformative development.” According to UCL, it remains uncertain whether these findings are applicable to individuals under 40, with definitive results expected several years in the future.