Grappling with metastatic risk: bringing molecular imaging of Met expression toward clinical use.

The availability of a test to assess the likelihood that a given tumor will invade or metastasize would be a useful development in clinical oncology. We propose that multimodality imaging of tumor expression of Met could serve as a prototype for metastatic risk stratification (MRS). Met, a receptor protein tyrosine kinase, is expressed by most solid tumors, and aberrant expression of Met is associated with poor clinical prognosis. We summarize the current status and predict the future direction of research in four areas of molecular imaging and cancer therapy that exploit Met.