TABLE 1.

Selection/Exclusion Criteria

Selection and Exclusion Criteria	Sample Size	Excluded
NCDB NET cancer cases	130,234	—
Include stage IV patients	24,028	106,206
Well/intermediate differentiated	5376	18,652
Exclude in situ	5376	0
Exclude patients with unknown surgical status for primary site	5358	18
Exclude patients who did not have pathologic confirmation	5341	17
Exclude CLASS OF CASE = 0*	4831	510
Include SEQUENCE_NUMBER in (0 1)†	4027	804
Exclude patients without follow up data	3342	685
Exclude patients who received surgery for the metastatic sites	2361	981

^*Classifies cases recorded in the database.

^†Indicates the sequence of malignant and non-malignant neoplasms over the lifetime of the patient.