Retrospective Cohort Study
Copyright ©The Author(s) 2021.
World J Clin Cases. May 26, 2021; 9(15): 3531-3545
Published online May 26, 2021. doi: 10.12998/wjcc.v9.i15.3531
Figure 1
Figure 1 Flowchart of patient selection. SEER: Surveillance, Epidemiology, and End Results Program; ELNs: Examined lymph nodes; PLNs: Positive lymph nodes.