Table 3.

Eligibility criteria review on genetic signatures and the presence of circulating tumor cells.

Study characteristics	Inclusion criteria	Exclusion criteria
Participants/population	Patients with primary neuroendocrine tumors	Children or adolescents (under the age of 18 years old).
	Patients whose genetic signatures of the primary tumor have been tested or those who have been tested for presence of circulating tumor cells	Animal studies
		Patients with tested genetic signatures only of the metastases
	Patients with 18 years of age or older
Test of interest	Gene expression testing of the primary tumor	Gene expression testing of the metastases
	Test for circulating tumor cells
Reference standard	The reference standard test will be the presence or absence of liver metastases during follow-up (imaging or histopathology) by presence or absence of a genetic signature or circulating tumor cells
Study design	Cross-sectional studies of any type	Case reports
	Cohort studies
Reporting		Studies that do not report any predictive value