Liver flukes and bile-duct cancer

Some liver-fluke infections are established risk factors for cholangiocarcinoma, a cancer of the bile ducts.

The National Cancer Institute identifies Opisthorchis viverrini as a parasitic flatworm that can cause cholangiocarcinoma. Risk is tied to a specific infection, exposure pattern and disease process—not to parasites as a single undifferentiated category.

See also the broader parasite–cancer evidence and our testing overview.