The application provides a
cancer primary focus tracing method, device,
system and storage medium, and relates to the technical field of
cancer tracing. The
cancer primary focus tracing method comprises the following steps: acquiring sample tissue data, giving each cancer sample a primary focus
label through a
methylation chip; determining candidate CpG sites; and constructing a cancer tracing classifier. The application realizes the technology of tracing multiple cancers by using
DNA methylation biological characteristics and
machine learning methods, and has the following characteristics: due to the high stability of
DNA molecules, cancer information is relatively completely retained, so that sample storage and transportation are more convenient; the cancers targeted by the application have a wide coverage range and include general common tumors; cancer-specific CpG sites have a wide coverage; through analysis of the cancer-specific sites, the interference of normal tissues is excluded, so that the accuracy and application range of the classifier are improved; and the high-precision classifier makes the cancer diagnosis process simpler, more accurate and more efficient.