Cost-benefit of serum pepsinogen screening for gastric adenocarcinoma in the Mexican population L.B. Enríquez-Sánchez; L.G. Gallegos-Portillo; J. Camarillo-Cisneros; M. Cisneros-Castolo; J.J. Montelongo-Santiesteban; D.A. Aguirre-Baca; A.I. Pérez-Echavarría; A.E. Contreras-Pacheco;