Photo of Prof. Allen CHAN

Prof. Allen CHAN

Deputy Scientific Director, Centre for Novostics

Tony Mok Professor of Medicine and Professor of Chemical Pathology, Department of Chemical Pathology

Assistant Dean (External Affairs), Faculty of Medicine



Professor Allen Chan is a co-inventor of the noninvasive prenatal test for Down syndrome. This technology has rapidly been adopted for clinical service with millions of tests performed each year globally. He has also pioneered the development of plasma DNA-based cancer tests (also known as liquid biopsy) and led the first large-scale trial to investigate if plasma DNA analysis is useful for cancer screening. Allen has filed over 2,500 patent applications in 86 families of inventions. He is named as one of the “Top Twenty Translational Researchers” by Nature Biotechnology in 2020.

Topic: Early Detection of Cancers by Plasma DNA Analysis


In cancer patients, DNA is released from tumor cells into blood plasma. The profiling of cancer-associated methylation changes in the circulating cell-free DNA represents a noninvasive means for the detection and monitoring of cancers. In addition, the detection of cancer-type specific alterations can provide information about the potential tissue origin of the cancer in subjects showing positive results. We used nasopharyngeal cancer as a model to demonstrate that analysis for cancer-associated DNA changes in plasma is useful for the screening of early asymptomatic cancers and result in improved patient survival. Another round of cancer screening was performed at 4 years after the first round of screening for the 20,000-subject cohort to address the long-term clinical significance of “positive results” in subjects without an immediately identifiable cancer.