The document discusses the role of sentinel lymph node biopsy in digestive cancers. It covers the history and techniques of sentinel lymph node mapping in stomach, colon, esophagus, liver and pancreas cancers. For stomach cancer, sentinel lymph node mapping shows potential to alter management of early-stage cancers and select patients for limited surgery. However, its accuracy decreases with increasing T stage. For colon cancer, sentinel lymph node mapping can upstage tumors and identify aberrant drainage but false negatives remain a issue. Further studies are still needed to establish standardized procedures and assess outcomes before it can significantly change treatment.