Liquid biopsy paves the way for improved cancer diagnosticsLiquid biopsy paves the way for improved cancer diagnostics

Cancer survival rates have improved significantly with the five-year survival rate increasing from 49 per cent in 1975 to 68 per cent in 2023, according to the American Cancer Society. While this progress offers relief, the emergence of advanced technologies like liquid biopsy (LBx) brings even greater hope. Unlike invasive needle biopsies, liquid biopsies offer a non-invasive blood test that detects cancerous tumours faster, safer, and more effectively, thus revolutionising cancer diagnosis and treatment.

Tumour DNA can be found in the bloodstream by a liquid biopsy, which can reveal important details about the genetic makeup of a tumour and show whether a treatment is effective. Liquid biopsies have a number of advantages, which include convenience, lower costs and faster results — about a week as opposed to two to three weeks for tissue biopsies. A non-invasive substitute is provided by liquid biopsies, which use blood tests to identify and track circulating biomarkers like exosomes, circulating tumour cells (CTCs), and cell-free DNA (cfDNA).

Though they cannot quite take the place of conventional biopsies just yet, liquid biopsies are a useful adjunct diagnostic method. Liquid biopsies have the potential to revolutionise cancer therapy and diagnostics as research into the disease continues.

Beyond initial diagnosis, liquid biopsies also play a crucial role in cancer management. They facilitate real-time monitoring of treatment responses, enabling oncologists to adjust therapeutic strategies based on dynamic changes in tumour biomarkers. This personalised approach, known as precision medicine, aims to optimise treatment efficacy while minimising adverse effects thereby enhancing overall patient care and quality of life.

Liquid biopsies show potential in the monitoring of minimal residual disease (MRD) following treatment. By identifying cancer cells that may persist after surgery or chemotherapy, these tests offer valuable information about the likelihood of a recurrence of the disease and help make judgments on the necessity of additional therapies or surveillance measures.

Despite encouraging developments, the field of liquid biopsies is not without difficulties. Research and development efforts should continue to focus on issues including sensitivity, specificity, and platform standardisation. Widespread clinical use of biomarker detection in blood samples depends on improving its precision and consistency, especially for malignancies with modest shedding rates or in their early stages.

The unpredictability in biomarker levels is a major obstacle for researchers and physicians working in the field of liquid biopsies. Tumour heterogeneity, load, and even the time of sample collection can all affect the concentration of circulating tumour DNA (ctDNA) or circulating tumour cells (CTCs) in a patient's blood.

The interpretation of liquid biopsy data is further complicated by the presence of false positives and false negatives. While false negative results may postpone critical therapeutic steps, false positive results may cause patients to experience unwarranted anxiety and extra testing. Technical difficulties in identifying low concentrations of ctDNA or CTCs may also be the source of these mistakes. Dr. Christine Bestvina, UChicago Medicine thoracic oncologist suggests that “some patients have unique DNA that can skew test results, making false positives a possibility."

There are further obstacles to the widespread use of liquid biopsies, including financial concerns and accessibility issues. Modern diagnostic technologies might be more costly than more conventional ones, which would restrict which patient populations and healthcare systems can use them. The realisation of liquid biopsies' full potential in cancer therapy will depend on addressing these cost concerns through technology advancements and healthcare policy measures.

As the field continues to evolve, it is essential to address the challenges and limitations of liquid biopsies, ensuring that this technology reaches its full potential and benefits patients worldwide. Ultimately, liquid biopsies are poised to make a significant impact on cancer diagnosis and treatment, offering a brighter future for those affected by this devastating disease.

References available on request.

Jennifer Orisakwe is a health researcher and data storyteller, who loves to explore the ways the actions (and inactions) of healthcare stakeholders affect decision-making and outcomes.