In 2023, Toronto resident Paul Lonergan underwent an arduous journey to diagnose his persistent sore throat, eventually discovering a large tumor at the base of his tongue. The 68-year-old embarked on a rigorous treatment regimen of seven weeks of radiation and chemotherapy, leading to intensive care unit visits to eradicate the tumor completely.
Despite the treatment, concerns remained about the cancer’s recurrence. Lonergan participated in a clinical trial that utilized a novel technique called “liquid biopsy.” This approach involves simple blood tests to detect tumor DNA remnants undetectable by conventional methods. The liquid biopsy revealed ongoing presence of tumor fragments in Lonergan’s blood, indicating potential cancer resurgence.
Subsequently, Lonergan underwent experimental immunotherapy, resulting in a cancer-free status confirmed by subsequent liquid biopsies. While liquid biopsy usage for cancer monitoring is limited in Canada to clinical trials and private facilities, experts believe in its transformative potential.
Dr. Ramy Saleh from McGill University Health Centre highlighted the revolutionary impact of liquid biopsies in disease surveillance. A Toronto-based team has initiated a large-scale research project, termed SHERLOCK, to explore integrating this technology into routine patient care for enhanced cancer surveillance and tailored treatments.
The ongoing clinical trial, led by scientists from the University Health Network, aims to assess over 7,000 cancer survivors using liquid biopsies over five years. Dr. Lillian Siu, the lead researcher, emphasized the project’s goal of identifying circulating tumor DNA signals for possible cancer recurrence, enabling early interventions and improved patient outcomes.
Despite the promise of liquid biopsies, ethical dilemmas and limitations exist, including false positives and negatives. Dr. Christopher Booth from Queen’s University raised concerns about the psychological impact of such screenings and emphasized the need for ongoing research to refine the technology’s efficacy and utility.
While liquid biopsies offer a potential paradigm shift in cancer care, challenges such as costs and regulatory approvals persist. However, experts like Dr. Saleh remain optimistic about the transformative impact of these tests, envisioning a future where liquid biopsies become routine and beneficial for a broader patient population.
The UHN research, set to conclude in 2031, aims to pave the way for widespread adoption of liquid biopsies in cancer care, potentially revolutionizing disease monitoring and treatment strategies globally.
