Tailoring Cancer Treatment: Genomic and Blood-Based Tests Show Promise in 2026 Studies

Genomic Test Identifies Breast Cancer Patients Who Can Safely Avoid Chemotherapy

A large international trial, known as OPTIMA (Optimal Personalised Treatment of early breast cancer using Multi-parameter Analysis), has reported that a genomic test can identify certain breast cancer patients who may not benefit from chemotherapy.

Trial Design and Participants

The trial enrolled 4,429 patients aged 40 and older with newly diagnosed, hormone-receptor positive breast cancer that had spread to lymph nodes. The study was conducted across the United Kingdom, Norway, Sweden, Australia, New Zealand, and Thailand, including 263 participants from Australia and New Zealand. It was run by Breast Cancer Trials in Australia and led by University College London.

Participants were randomly assigned to one of two groups:

• Standard treatment: Chemotherapy followed by hormone-blocking therapy.
• Test-directed group: Treatment was guided by the Prosigna genomic test. Patients with a low-risk score received hormone therapy alone, while those with a high-risk score received both chemotherapy and hormone therapy.

The Prosigna test, manufactured by Veracyte, analyzes the activity of 50 genes in tumor tissue to determine the molecular subtype and estimate the 10-year risk of recurrence.

Results

Over two-thirds (68%) of participants had a low Prosigna score (≤60).

Five-year cancer-free survival rates:

• Patients who received chemotherapy plus hormone therapy: 94.8%
• Patients who received hormone therapy alone (low-risk group): 93.6%

Statistical analysis indicated that at most 2% of patients with a low Prosigna score benefit from adding chemotherapy.

Outcomes were similar for pre-menopausal and post-menopausal women. Pre-menopausal women in the study received ovarian function suppression as part of their hormone therapy.

Statements

Australian Study Chair A/Prof Belinda Kiely stated that the trial used tumor biology to guide treatment, noting that for low Prosigna scores, chemotherapy offers little or no additional benefit. Prof Rob Stein, the trial's chief investigator, stated that the results address a long-standing challenge in breast cancer care. Prof Iain MacPherson, co-chief investigator, described the evidence as practice-changing and noted the potential to reduce chemotherapy use.

Impact

The results indicate that patients aged 40 and older with hormone-receptor positive breast cancer and a low Prosigna score can safely avoid chemotherapy. Applicability to patients under 40 is not yet known; the next phase of the study will focus on pre-menopausal women. The trial was funded by the National Institute for Health and Care Research, Veracyte, and cancer charities. Findings were presented at the 2026 American Society of Clinical Oncology (ASCO) annual meeting in Chicago.

Blood Test May Guide Radiotherapy for Oligometastatic Cancer

A randomized controlled trial presented at the ESTRO 2026 meeting suggests that a blood test measuring circulating tumor DNA (ctDNA) can help identify which patients with oligometastatic cancer benefit from adding radiotherapy to drug therapy.

Study Design

The study involved 237 patients with 1–5 metastases across six cancer subgroups. Patients were randomized to receive drug therapy alone or drug therapy plus radiotherapy. Blood samples were collected at baseline, after three months, and at progression to measure ctDNA.

Findings

• Patients with detectable ctDNA at baseline had higher rates of cancer progression and mortality.
• Radiotherapy combined with drug therapy improved ctDNA clearance compared to drug therapy alone.
• Clearance of ctDNA was associated with better outcomes and survival.
• Persistent ctDNA after therapy may indicate aggressive disease, ineffective treatment, or undetected metastases.

Statements

Dr. Alex D Sherry (Mayo Clinic), who presented the study, noted that the results support using targeted treatments like radiotherapy in oligometastatic cancer. Dr. Guckenberger, ESTRO President, stated that the non-invasive test could complement imaging for more precise treatment planning. The study was published in the Journal of Clinical Oncology.

Blood Test Predicts Non-Small Cell Lung Cancer Treatment Response

A study led by the University of Queensland (UQ) has demonstrated that a single blood test could help predict how patients with non-small cell lung cancer (NSCLC) will respond to treatment before therapy begins.

Research Methods

The research was published in npj Precision Oncology. Researchers collected blood samples from patients before and after surgery and immunotherapy. They measured thousands of proteins and applied statistical modeling to identify signals associated with treatment response and disease progression. The findings were validated on an independent testing platform.

Statements

Associate Professor Arutha Kulasinghe from UQ's Frazer Institute stated that the approach could enable clinicians to use a patient's own biology to guide treatment decisions at diagnosis. He noted that treatment decisions are currently often made without a clear picture of how a patient will respond. Researchers indicated that blood-based monitoring would be less invasive than repeat biopsies and could provide earlier warning of recurrence. The team is exploring whether the method can be applied to other cancers.

DNA Blood Test Predicts Advanced Breast Cancer Treatment Response

Researchers at the Institute of Cancer Research (ICR), London, developed a liquid biopsy that analyzes circulating tumor DNA (ctDNA) released into the bloodstream by cancer cells to predict a patient's likely response to specific treatments.

Methodology

The test was trialed using blood samples from 167 patients with advanced breast cancer. Samples were collected before treatment and again four weeks after the first treatment cycle.

Key Associations

• A strong association was observed between low ctDNA levels at the start of treatment and a positive treatment response.
• Similar associations were found with ctDNA levels measured after four weeks of treatment.

Patient Group Outcomes

Group 1 (Specific Mutations): Patients with ESR1, HER2, AKT1, AKT, or PTEN mutations received targeted treatments. After four weeks of treatment:

• Patients with undetectable ctDNA: median progression-free survival of 10.6 months
• Patients with detectable ctDNA: median progression-free survival of 3.5 months

Group 2 (Triple-Negative Breast Cancer): Patients received a combination of the PARP inhibitor olaparib and the ATR inhibitor ceralasertib.

• Low pre-treatment ctDNA levels: median progression-free survival of 10.2 months (vs. 4.4 months for higher levels)
• Treatment response rate: 40% for low ctDNA vs. 9.7% for higher levels
• After four weeks: undetectable ctDNA patients maintained cancer control for a median of 12 months (vs. 4.3 months for detectable ctDNA)

Statements

Dr. Iseult Browne, a clinical research fellow at the ICR, stated that early prediction of treatment response allows for the avoidance of ineffective drugs and the provision of alternative therapies. Prof. Nicholas Turner, a professor of molecular oncology at the ICR, suggested these tests could also be applied to early-stage breast cancers.

DNA Barcoding Improves Understanding of Biopsy Accuracy

Australian scientists have used DNA barcoding technology to track cancer cells in both solid and liquid biopsies, providing insights into how these methods capture tumor diversity.

Research Methods

Researchers from the Olivia Newton-John Cancer Research Institute (ONJCRI), WEHI, and Peter MacCallum Cancer Centre optimized a DNA barcoding technique that uses lentiviruses to label individual cancer cells with unique DNA tags. These tags function as barcodes, allowing researchers to track and identify cells in tumors and matched biopsies.

Findings

• Tumors in different models shed varying amounts of DNA into the bloodstream, even when their cancer cell composition appeared similar.
• For the first time, the team detected DNA barcodes shed by the primary tumor in blood and plasma samples.
• Varying detectability of DNA tags across models suggests that DNA shedding is model-specific and could lead to false-negative liquid biopsy results.
• Barcode diversity in the center of primary tumors was significantly higher than in the periphery, which could affect solid biopsy interpretation.

Statements

Dr. Antonin Serrano, a Postdoctoral Researcher at the University of Melbourne, stated that DNA barcoding allowed quantification of tumor heterogeneity captured in biopsies. Professor Delphine Merino, Laboratory Head at ONJCRI, indicated that results suggest both liquid and solid biopsies generally represent tumor composition, but combining both strategies may offer a more accurate representation. Professor Sarah-Jane Dawson, co-senior author, noted that liquid biopsies are a non-invasive way to monitor disease progression and that this research could improve clinical use of liquid biopsies.