S100P and digestive system cancer: When stratified by anatomic structure, S100P overexpression was associated with poor prognosis in non-gastrointestinal tract cancers (HR=1.98, 95% CI: 1.44-2.72, P<0.001) but not in gastrointestinal tract cancers (HR=1.09, 95% CI: 0.66-1.81, P=0.727).