The present disclosure provides methods and systems for screening or detecting
colorectal cancer or subsequent colorectal
disease progression, which can be applied to
cell-free nucleic acids, such as
cell-
free DNA. The methods can
train a
machine learning model using detection of
methylation signals within single sequencing reads in identified genomic regions as input features, and generate a classifier suitable for stratifying a
population of individuals. The methods can include extracting
DNA from a
cell-free sample obtained from a subject, transforming the
DNA for
methylation sequencing, generating sequencing reads, and detecting colon proliferative cell disorder related signals in the sequencing information, and training a
machine learning model to provide a
discriminator capable of distinguishing between groups such as healthy,
cancer, etc. in a
population of subjects, or distinguishing between
disease subtypes or stages. The methods can be used, for example, to predict, prognosticate, and / or monitor
response to treatment,
tumor burden, recurrence, or progression of
colorectal cancer.