By Nana Karikari, Senior Global Affairs Correspondent
The global approach to breast cancer treatment faces a significant shift following the release of landmark clinical trial data. Millions of patients worldwide may soon safely bypass chemotherapy.
An international study demonstrates that a specialized genomic test successfully identifies which individuals require the aggressive treatment and which individuals can safely skip it. The findings will be presented at the annual meeting of the American Society of Clinical Oncology in Chicago on Saturday.
A Shift Toward Personalised Medicine
Breast cancer remains the most prevalent form of cancer globally. For decades, standard care has dictated surgery to remove tumors, followed by chemotherapy to lower the risk of recurrence. This standard applies even when the disease is in its early stages or has spread to nearby lymph nodes.
Clinicians have long questioned the necessity of this approach for everyone. The treatment frequently provides little benefit to individuals with hormone-positive breast cancer, which accounts for up to 80% of all global cases.
The Optima trial, led by University College London (UCL), evaluated 4,429 patients aged 40 and older across the United Kingdom, Norway, Sweden, Australia, New Zealand, and Thailand. Researchers utilized a genomic test called Prosigna, manufactured by Veracyte, to analyze the activity of 50 genes within tumor tissue. The test calculates a specific score indicating the risk of the cancer returning over the next decade.
Comparable Outcomes Without Toxic Side Effects
The randomized trial divided participants into two distinct categories. The first group received standard care consisting of chemotherapy followed by hormone therapy. The second group underwent the Prosigna genomic test to dictate care.
Within the tested group, patients with high risk scores received both chemotherapy and hormone therapy. Patients with low risk scores skipped chemotherapy entirely and received hormone therapy alone. Both groups received radiotherapy as standard.
The data revealed nearly identical survival and recurrence outcomes between the two approaches. Depending on the specific statistical rounding models analyzed across the trial arms, approximately 94% to 95% of patients who received chemotherapy and hormone therapy were alive and free from recurrence after five years. Among the patients with low test scores who skipped chemotherapy, a near-identical 93.7% to 94% were alive and recurrence-free.
For the two-thirds of patients who scored low on the test, chemotherapy provided no statistical advantage.
Alleviating the Burden on Patients
Chemotherapy carries a heavy physical and emotional toll. The treatment causes immediate side effects including nausea, fatigue, hair loss, rashes, insomnia, and a weakened immune system. It can also lead to permanent, life-changing complications such as cognitive impairment, early menopause, and infertility.
For patients who qualify to skip the treatment, the change in protocol alters the entire experience of cancer recovery.
Karen Bonham, a 64-year-old participant from Cardiff, avoided chemotherapy based on her low Prosigna test score. She instead received eight years of radiotherapy and hormone therapy, and she remains healthy nine years after her diagnosis.
“Cancer diagnosis and treatment can be shocking,” Bonham said. “It certainly propels you into a world of uncertainty. Life priorities realign – you simply want to survive.”
Bonham noted that learning she could safely avoid chemotherapy provided “immense relief” and felt “like Christmas.”
Transforming Global Healthcare Systems
The implications of the Optima trial extend beyond individual patient well-being to the operational structure of international healthcare providers. In the United Kingdom alone,
UCL estimates that more than 5,000 National Health Service (NHS) patients per year can now safely avoid chemotherapy.
Professor Rob Stein, the trial’s chief investigator and a professor of breast oncology at the UCL Cancer Institute, emphasized the structural and human impact of the data.
“Optima addresses a longstanding challenge in breast cancer care: identifying who truly benefits from chemotherapy and who does not. Our findings show that many patients can safely avoid chemotherapy without compromising their outcomes,” Stein said. “These results mark an important and significant step toward more personalised treatment. The trial has successfully used tumour biology to guide decisions rather than relying solely on traditional clinical features.”
Stein added: “For patients, this means many may be spared the physical and emotional burden of chemotherapy and its potential long-term side effects. For health systems, it represents a more efficient and evidence-based use of resources.”
Limitations and Future Research
While the trial offers clear direction for specific demographics, certain variables require further study. The funding for the research was provided by the National Institute for Health and Care Research, Veracyte, and various cancer charities.
A small number of male breast cancer patients participated in the trial. However, the sample size was too limited to draw definitive clinical conclusions for men.
Additionally, the current data applies only to patients aged 40 and older. It remains unknown whether these genomic testing thresholds can be safely applied to patients under the age of 40. According to UCL, definitive data for younger patients is still several years away.
Nevertheless, medical experts view the trial as a definitive turning point for oncology guidelines.
“Optima provides robust, practice‑changing evidence that we can safely reduce the use of chemotherapy for many patients with hormone‑sensitive breast cancer,” said Professor Iain MacPherson, a co-chief investigator from the University of Glasgow. “These findings represent a major step forward in delivering more personalised, precise care, ensuring that treatment decisions are driven by what will genuinely improve outcomes for patients, while avoiding unnecessary toxicity. The potential impact for both patients and health services is substantial.”
Navigating Access and Equity Across Africa
The potential to eliminate the financial and physical toll of chemotherapy holds profound significance for Sub-Saharan Africa, where breast cancer is the leading cause of female cancer mortality. For African patients, the economic burden of oncological care is often catastrophic, frequently forcing families to pay entirely out of pocket for expensive cytostatic drugs and supportive treatments.
However, medical experts emphasize that bridging the gap between international clinical breakthroughs and regional deployment requires overcoming steep infrastructure hurdles. Advanced molecular diagnostics like the Prosigna genomic test are currently scarce across the continent. In Ghana, for instance, advanced pathology and oncology services remain heavily concentrated in a few premier public institutions, such as Korle-Bu Teaching Hospital in Accra and Komfo Anokye Teaching Hospital in Kumasi, leaving rural populations with severely fragmented access to early diagnostic care.
Furthermore, existing healthcare frameworks like Ghana’s National Health Insurance Scheme face ongoing challenges in absorbing the high costs of complex diagnostic assays. While avoiding chemotherapy could eventually save regional healthcare budgets millions in drug procurement, public and private sectors must collaborate through initiatives like the African Access Initiative to decentralize advanced laboratories. Without deliberate policy interventions to subsidize genomic testing, the life-saving benefits of personalized medicine risk remaining out of reach for the vast majority of African patients.
The Horizon of Oncological Care
The success of the Optima trial underscores a broader, ongoing paradigm shift in global oncology away from blanket treatments and toward highly precise, biology-driven care. By proving that genomic tracking can safely prevent over-treatment, the study sets a new benchmark for balancing patient quality of life with rigorous clinical efficacy. As health systems prepare to integrate these findings into updated international guidelines, the medical community moves one step closer to an era where the toxicity of cancer treatment is deployed only when absolutely necessary.
