FDG-PET-CT is effective in selecting patients with poor long term survivals for colorectal liver metastases

Having incorporated PET-CT as part of the staging process for colorectal liver metastases (CRLM) in our unit since 2008, this study aims to evaluate the survival outcomes of all patients managed by our specialist multi-disciplinary team (MDT).

All patients with colorectal liver metastases referred to a single liver MDT between 2008 and 2011 were examined. Overall survival (OS) for palliative groups due to occult extrahepatic disease detected by PET-CT (A) and those upfront palliative patients with extensive multi-site disease as identified on baseline CT or disease progression during chemotherapy (B), and resected (C) groups were evaluated and compared. Different extents of occult extrahepatic disease as characterised by PET-CT were also compared.

532 patients were included in the study. Median OS for group A (n = 80), B (n = 161) and C (n = 291) were 10.9, 12.0 and 46.7 months, with a 5-year OS approaching 6.5%, 6.1% and 43.0% respectively. There were significant differences in OS of C vs. A & B (p < 0.001). Single compartment metastases had a significant better survival outcomes than non-torso metastases (p = 0.04).

This is the first report of OS of patients with CRLM excluded from surgery on the basis of PET-CT. We have confirmed that PET-CT is effective in selecting patients with occult extrahepatic disease, which has poor survival outcomes. However, a subgroup with single compartment extrahepatic disease has a better than expected outcome.