[Immunotherapy for gastrointestinal cancer].

Cancers of gastrointestinal tract make up the largest group of solid tumour diseases in Germany. The prognosis at diagnosis is often critical. Drug therapies reduce the risk of relapse after resection and can halt the progression of metastatic disease. Immunotherapies contribute increasingly to the treatment of gastrointestinal tumours. Monoclonal antibodies (mAB) against surface receptors from the epidermal growth factor receptor family (EGFR, Her2) are well established. The effect is partly based on the interruption of the oncogenic downstream signalling cascades and partly on immune effector mechanisms such as antibody-dependent cellular cytotoxicity. In clinical practice mAB directed against programmed cell death protein 1 (PD-1), its ligand (PD-L1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) - so-called immune checkpoint inhibitors - play an increasing role and change the natural history of some subgroups of gastrointestinal cancers, especially those with deficient DNA mismatch repair which leads to genomic microsatellite instability.