Authors: Jaffer A. Ajani, Katrina S. Pedersen
Published: 2024-05-31
Source: Full article
Microsatellite status should be assessed in all upper and lower gastrointestinal (GI) cancers. If an upper GI cancer is microsatellite instable (MSI), clinicians should consider treatment with an immune checkpoint inhibitor (ICI) or a combination of ICIs instead of chemotherapy. Immunotherapy is also active in lower GI cancers, where treatment is driven by microsatellite status. For upper GI cancers, the benefit has mostly been shown in the neoadjuvant and metastatic settings. In colorectal cancer, most of the benefit has been established in metastatic disease, although the use of immunotherapy in the neoadjuvant and adjuvant settings is an active area of research. In rectal cancer, a response benefit has been established for ICI as neoadjuvant therapy, although survival outcomes have not matured.