Our team has published new real-world evidence study addressing a rare, but clinically challenging scenario: microsatellite instability–high (MSI-H) colon cancer presenting with isolated peritoneal metastases (iPM) (Metzger et al., Cancers, 2025).
Leveraging national outcomes data, this study demonstrates:
Immunotherapy is associated with significantly improved overall survival compared with chemotherapy alone (33 vs. 18 months).
Surgical resection, with or without metastasectomy, confers survival benefit.
The greatest survival advantage is observed when immunotherapy and surgery are combined, supporting an integrated multimodal treatment approach.
These findings challenge traditional paradigms that often discourage surgery in metastatic disease and highlight the biologically distinct nature of MSI-H iPM. The data support a treatment strategy that leverages both systemic immunotherapy and local control to improve patient outcomes.
This work reflects a productive collaboration led by Dr. Despina Siolas and Dr. Dorna Jafari, with contributions from colleagues at Weill Cornell Medicine and collaborating institutions.