Table 1.

Application of PICOS criteria for study inclusion

Parameter	Criteria
Participants	Inclusion criteria: 1)  ≥ 18 years adults 2) With or without cancer
	Exclusion criteria: 1) Have any mental disorders 2) Whose blood sample cannot be got for any reason, etc.
Intervention/exposure	Patients with cancer or patients with high level SFA
Comparison	Patients without cancer or patients with low level SFA
Outcome	A dichotomous outcome: cancer or no cancer diagnosis. (can be overall or site-specific cancer)
Study design	Observational study, mainly case-control and cohort. Only human studies were considered, no animal studies