Table 1: Summary of evidence linking gastrointestinal parasites and neoplasia.

ParasiteCancer typeSiteTypes of studiesProbability of causation of neoplasia

S. japonicumAdenocarcinomaColon and rectumCase-control studies, epidemiological studies, case series, and many case reportsProbable
S. mansoniAdenocarcinomaColon and rectumCase-control studies, case reportsEquivocal, weak association
E. histolytica AdenocarcinomaColonRare case reportsUnlikely
A. lumbricoides AdenocarcinomaBiliary tract and ampullaRare case reportsUnlikely
AnisakisAdenocarcinomaColonRare case reportsUnlikely
G. lambliaDuctal adenocarcinomaPancreasRare case reportsUnlikely