Early Detection of Five Common Cancers Using the ctDNA Analysing Test

This is a multi-centre, prospective cohort study, aiming to evaluate a blood test in early detection of the four common cancers, based on the investigation of the circulating tumour DNA (ctDNA).
Primary objective: To evaluate the performance characteristics of the blood ctDNA test in early detecting cancers.
Secondary objectives:
* To evaluate the performance characteristics of the test in determining the origin of tumour, as compared to the findings of the imaging diagnostic tests.
* To determine the risk of cancers development in the high-risk population, as compared to that in the moderate-risk group.