Theranostic radiopharmaceuticals targeting cancer-associated fibroblasts

The tumor microenvironment is a dynamic ecosystem where malignant cells interact with the stromal cells sustaining and promoting tumor growth and metastasis. Cancer-associated fibroblasts (CAFs) are the major component of tumor stroma. CAFs control key tumorigenic activities by participating in immune evasion and suppression, extracellular matrix remodeling, neo-angiogenesis, and drug resistance. Therefore, targeting CAFs emerges as an attractive anti-cancer strategy. This review summarized recent advancements in targeting CAFs with diagnostic and therapeutic radiopharmaceuticals using clinically-promising biomarkers. The efforts to improve clinical outcomes via application of new radiotheranostic compounds are discussed in the context of radionuclide, the pharmacophore, and, more generally, in terms of biomarker specificity and expression across different cancers and CAF phenotypes.