Belgium’s precision oncology faces a critical gap in breast cancer care. Advanced diagnostics, including next-generation sequencing (NGS) are available, but the corresponding targeted therapies are not reimbursed. This disconnect is leaving many patients unable to fully benefit from the precision medicine potential.

Similar disparities exist across Europe, where access to advanced diagnostics persists. While basic biomarker testing techniques such as immunohistochemistry (IHC) are widely accessible, advanced technologies like NGS and liquid biopsies are often limited to clinical trials or research settings.

Barriers such as healthcare budget pressures, uneven reimbursement, and infrastructure challenges prevent these transformative tools from reaching all patients.

Recognising these issues, the Transforming Breast Cancer Together (TBCT) initiative has highlighted stark disparities in breast cancer care across Europe.

TBCT has shed light on unequal access to diagnostics, treatments, and support services, while also showcasing best practices from across the continent.

Central to its recommendations is a call for a unified European strategy to address these gaps and ensure equitable access to advanced diagnostics and therapies.

Diagnostics disconnect

The Institut Jules Bordet, a comprehensive cancer centre affiliated with the Université Libre de Bruxelles (U.L.B.), exemplifies Belgium’s progress in precision oncology. Treating approximately 700 breast cancer patients annually, the Institute is also home to the Breast International Group (BIG) – the world’s largest clinical and translational breast cancer research network.

Among its key contributors is the Breast Cancer Translational Research Laboratory J.C. Heuson (BCTL), directed by Professor Christos Sotiriou, MD, PhD. The BCTL bridges basic and clinical research, focusing on understanding breast tumour genesis and drug resistance.

It has developed several prognostic and predictive tools, including the Genomic Grade Index (GGI), and led the AURORA study, which provides molecular insights into metastatic breast cancer.

Despite these advancements, challenges remain in integrating tools like NGS into clinical practice in Belgium.

“NGS is available, but several drugs associated with these mutations are still not reimbursed in Belgium for breast cancer patients,” Professor Sotiriou told Euractiv.

This gap prevents patients from accessing therapies for actionable mutations, even when identified.

“There are now drugs that work well if the patient has that mutation, but we still need reimbursement to make these accessible,” he noted.

Liquid biopsies, precision oncology

One of the most promising advancements in breast cancer diagnostics is the use of liquid biopsies, which analyse circulating tumour DNA (ctDNA) to provide real-time insights into disease progression.

According to Professor Sotiriou, liquid biopsies could revolutionise post-surgical care by enabling the detection of minimal residual disease (MRD).

“Liquid biopsies could revolutionise how we detect minimal residual disease after surgery. This could help avoid over-treatment for patients without residual tumour cells,” he explained.

The ability to detect MRD would allow clinicians to tailor post-operative treatments more precisely, sparing patients unnecessary therapies and minimising side effects.

“We need better tests to detect MRD and avoid over-treatment. It’s the next step in precision oncology,” said Sotiriou.

There are currently ongoing prospective studies that evaluate the prognostic and predictive value of testing MRD in the early setting for breast cancer patients.

However, the costs and limited reimbursement remain barriers to the widespread adoption of liquid biopsies in Belgium, further underscoring the systemic challenges in aligning innovation with equitable access.

Liquid biopsy testing is also the preferred method to detect ESR1 mutations.

Almost one in two patients with ER+/HER2 metastatic breast cancer develop resistance to hormone therapy, leading to disease progression, due to mutations on ESR1 (Estrogen receptor 1), the target for the hormone treatment. ESR1 mutations are sub clonal and heterogeneous within the tumour – not all of them will be detected in a tissue biopsy.

Blood-based ctDNA is considered the preferred testing methodology, and ESR1 liquid biopsy testing should happen at each disease progression.

Long road to reimbursement

Belgium’s experience reimbursing biomarker tests illustrates the challenges of integrating advanced diagnostics into clinical practice. Two tests, MammaPrint and Oncotype DX, highlight this journey.

MammaPrint, developed in Europe, analyses 70 specific genes in breast tumours to predict the likelihood of metastasis and assess tumour aggressiveness. Similarly, the Oncotype DX, developed in the United States, provides comparable insights into early-stage breast cancer prognosis and treatment planning.

Despite their clinical utility, these tests faced years of debate before reimbursement was approved. It wasn’t until 2019, that Belgium began reimbursing biomarker tests like MammaPrint and Oncotype DX, and even then, access was limited to early-stage breast cancer patients treated at accredited breast cancer clinics.

Professor Sotiriou reflected on the resistance to these tools, saying “It was very tough. Many oncologists believed they could predict prognosis using traditional parameters, which were far less accurate.”

Belgium lagged behind countries like the U.S., Greece, and Italy in adopting these tests.

“It was bizarre to see how nations with fewer resources were ahead of us in integrating these tools,” he remarked.

Resistance stemmed from debates over cost-effectiveness, clinical utility, and internal disagreements among clinicians and policymakers.

Calls for unified action

Across Europe, access to advanced biomarker technologies like NGS and liquid biopsies remains highly variable.

While basic techniques are widely available, advanced technologies are often restricted to clinical trials or research settings due to barriers like reimbursement, lack of corresponding therapies, and funding constraints.

To address these disparities, Dr. Fatima Cardoso of TBCT advocates for a unified European strategy. She said: “Europe should consider developing a comprehensive genetic and genomic testing strategy for breast cancer. Unified standards would ensure equitable access to high-quality testing and personalised treatments across all member states.”

TBCT has called for a European Commission initiative to address these gaps and standardise access to advanced diagnostics, emphasising the critical role of biomarker technologies in transforming cancer care.

Belgium’s advancements, led by institutions like the Jules Bordet Institute, demonstrate the potential of precision oncology.

However, without aligned reimbursement policies and equitable access to advanced biomarker technologies, many patients remain unable to benefit fully from these innovations.

“It’s frustrating, but this is the future,” Sotiriou added.

[Edited by Vasiliki Angouridi, Brian Maguire]