Liver and peritoneal metastases of unknown primary site: French Intergroup Clinical Practice guidelines for diagnosis, treatment, and follow-up (TNCD, SNFGE, FFCD, UNICANCER, GERCOR, SFCD, SFED, SFP, SFR, ACHBT, SFRO, SNFCP, AFEF, RENAPE, NET-CAPI)
Cet article présente les recommandations de sociétés savantes françaises concernant le diagnostic, le traitement et le suivi de métastases hépatiques ou péritonéales
Introduction : This document is a summary of the French intergroup guidelines for the management of liver and peritoneal metastases developed within the « cancer of unknown primary » (CUP) syndrome, published in April 2025, and available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org).
Methods : This collaborative work was conducted under the auspices of French medical and surgical societies involved in the management of CUP. Recommendations were graded in four categories (A, B, C and D) according to the level of scientific evidence until April 2025.
Results : The diagnosis of liver and peritoneal metastases of unknown primary rely on a complex diagnostic work-up combining computed tomography and magnetic resonance, endoscopy, and biopsy of a metastatic site for extensive pathological characterization. Early systematic molecular profiling is recommended to identify a putative tissue of origin using molecular classifiers and to detect potential targetable alterations. Treatment strategies differ according to general condition, metastatic sites and pathological and molecular characteristics, and must be discussed in expert multidisciplinary tumour boards (MTB). Empiric platinum-based chemotherapy remains the gold standard for undifferentiated neoplasms of unknown primary. Systemic treatments oriented by the molecular profile must be proposed whenever possible. Surgery can be proposed to patients with oligometastatic disease and to patients with resectable and isolated peritoneal disease. Other local treatments can be discussed in favourable cases. No standard second-line systemic treatment has been validated to date.
Conclusion : These guidelines are intended to provide a state-of -the art management for daily clinical practice. Each individual CUP case should be discussed by a dedicated MTB.
European Journal of Cancer , article en libre accès, 2026