Blood test for early cancer detection shows promise
In a landmark study, researchers from the Chinese University of Hong Kong have found that plasma Epstein-Barr virus (EBV) DNA screening is instrumental in the early detection of nasopharyngeal cancer (NPC) and can accurately indicate future cancer risk. This significant research has been published in NEJM Evidence, a publication of the New England Journal of Medicine Group. To view the scientific paper click here.
NPC is one of the most aggressive head and neck cancers, known for frequent metastasis to distant lymph nodes and organs. It is particularly common in Hong Kong and other parts of Southern China, with an incidence rate of 35 per 100,000 middle-aged men every year in endemic areas. The detection of cancer-derived EBV DNA in blood plasma has been shown to aid in identifying NPC patients.
The CUHK research team conducted plasma EBV DNA screenings on over 20,000 middle-aged, asymptomatic men from 2013 to 2016. The initial round of screening led to the detection of 34 NPC cases, while those without cancer detection were marked as false positives.
Participants with no cancer detected in the first round underwent a second round of testing three to five years later. The second screening identified an additional 24 NPC cases, with about 70% of these being early-stage NPC (stages I or II). This contrasts sharply with the mere 20% of early-stage cancers detected in patients who had not undergone screening, thereby underlining the importance of plasma EBV DNA screening for early detection of NPC.
Impressively, the research team found a striking correlation between the first and second round screenings. Participants with persistently positive plasma EBV DNA results in the first round were about 17 times more likely to be diagnosed with NPC in the second round compared to those with no detectable plasma EBV DNA.
Professor Allen Chan, Professor of Chemical Pathology at CUHK, highlighted the significance of these findings. “Our results underscore the clinical importance of plasma EBV DNA positivity. The detection of cancer-associated EBV DNA in plasma not only indicates the presence of a current NPC but can also reflect the risk of developing the cancer in the future,” he stated.
Professor Dennis Lo FRS, Director of the Li Ka Shing Institute of Health Sciences at CUHK, echoed this sentiment:“Plasma DNA-based tests are increasingly used for the screening of various types of cancer. In a proportion of test-positive subjects, no cancer could be identified after further investigation. Our large-scale prospective study demonstrated that detection of cancer-related DNA changes in a blood test also reflects an increased risk of cancer in the future. In addition to NPC, it is possible that this phenomenon might also be seen for other cancers. In addition to detecting early asymptomatic cancers to improve the survival rate of patients, it can predict the future cancer risk of subjects so that they can take appropriate management measures, such as more frequent follow-up to look for emerging cancers.”
This research represents a significant leap forward in the realm of early cancer detection and future risk prediction. With continued work, these findings have the potential to revolutionize cancer screening practices, potentially saving countless lives through early detection and intervention.
Professor Dennis Lo Yuk Ming, FRS
Professor Dennis Lo is the Director of the Li Ka Shing Institute of Health Sciences, the Li Ka Shing Professor of Medicine and Professor of Chemical Pathology of The Chinese University of Hong Kong (CUHK). He is also the Associate Dean (Research) of the Faculty of Medicine of CUHK. Lo received his Bachelor of Arts degree from the University of Cambridge and the Doctor of Medicine and Doctor of Philosophy degrees from the University of Oxford. Following his training at Oxford, he was appointed as the University Lecturer in Clinical Biochemistry and Honorary Consultant Chemical Pathologist at the John Radcliffe Hospital, the teaching hospital of the University of Oxford Clinical School. He was also a Fellow at Green College, Oxford. Lo returned to Hong Kong to join the Medical Faculty of CUHK in 1997. In the same year, he discovered the presence of fetal DNA in maternal plasma. His group has fundamentally changed our understanding of the biology of this phenomenon and its diagnostic applications. In particular, Lo’s group has pioneered technologies for the non-invasive prenatal testing of Down syndrome, which have created a paradigm shift in prenatal medicine. He received the Future Science Prize – Life Science Prize in 2016 for his seminal contribution to the widely-used non-invasive prenatal test based on the original discovery of fetal DNA in maternal blood which has benefited millions of pregnant women globally. Lo is a Fellow of the Royal Society, a Foreign Associate of the US National Academy of Sciences and a Fellow of the World Academy of Sciences. He won the King Faisal International Prize in Medicine in 2014 and was awarded a Croucher Senior Medical Research Fellowship in 2006.