The invention relates to the technical field of
molecular biology, in particular to application of a
gene marker in early screening of multiple alimentary canal
cancer species, an early screening model construction method and a detection device.WGS low-depth sequencing is conducted on
plasma sample cfDNA, and three difference characteristics including copy number change, copy number change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change, cfDNA fragment change and cfDNA fragment change are analyzed according to a high-
throughput sequencing result. The method comprises the following steps of: performing training modeling by using a
convolutional neural network according to
a DNA fragment size ratio and a
nucleosome covering mode, realizing high-specificity and high-sensitivity accurate
early detection on a plurality of cancers under low sequencing depth, and performing training modeling by using five algorithms, namely a
generalized linear model,
gradient boosting, a
random forest,
deep learning and
extreme gradient boosting respectively, so as to realize accurate
early detection on the plurality of cancers under low sequencing depth. The
generalized linear model is subjected to secondary set training to construct multi-feature
algorithm integration, and the purpose of tissue
traceability detection of
multiple cancer species is achieved.