Developing a blood test to improve detection of head and neck cancer recurrence

Dr. Enrique Sanz Garcia will use a 2026 MOHCCN Clinician-Scientist Award to study whether plasma whole-genome sequencing can detect recurrence months before it appears on scans.

After receiving treatment, patients with locally advanced head and neck cancers undergo scans and physical examinations to look for signs that their cancer has returned. But these approaches can only detect recurrence once disease has grown large enough to be seen, potentially allowing cancers to develop silently for months.

“There is a huge clinical gap day what we can see and what may actually be happening biologically,” says Dr. Enrique Sanz Garcia, a clinician investigator at UHN’s Princess Margaret Cancer Centre who treats patients with this type of cancer. “Using today’s approaches, by the time recurrence is detected, the disease is often more advanced and harder to treat.”

To address this gap and bring better care to these patients, Dr. Sanz Garcia will use new funding from a 2026 Marathon of Hope Cancer Centres Network (MOHCCN) Clinician-Scientist Award to develop a blood test that searches for tiny fragments of tumour DNA circulating in a patient’s bloodstream using a technology called plasma whole-genome sequencing.

By the end of the three-year project, the team hopes to show that the test is both scientifically reliable and clinically meaningful. They will examine whether it can detect recurrence months before scans, investigate why some tumours release more DNA into the bloodstream than others, and explore whether the test can help predict response to treatments such as immunotherapy.

“If these tests work, we could identify recurrence much earlier, intervene sooner, and improve outcomes for patients,” he says. “Our goal through this project is to generate the evidence needed to design a future clinical trial where treatment decisions are guided by this blood test.”

As part of the award, Dr. Sanz Garcia will receive a total of $525,000 over three years, with $262,500 coming from the Network and matching funds coming from University Health Network and Ontario Institute of Cancer Research. In addition to funding the project, this early career award will help him continue to develop a robust research program at the intersection of clinical care and genomics, lead studies with direct relevance to patients, and continue bridging the gap between research and the clinic.

“It’s a tremendous honor to receive this award, especially from an initiative like the Marathon of Hope, which has such a strong focus on improving outcomes for patients,” he says. “For me, this award represents both recognition and responsibility, providing resources to pursue an important research question, but also an opportunity to contribute meaningfully to the field.”