Angiogenesis in Y-90-Radioembolization of Colorectal Liver Metastases

In order to evaluate the role of angiogenesis in ⁹⁰Y-radioembolization for colorectal cancer liver metastasis an overview was provided of angiogenic growth factors and their function, the angiogenic mechanisms in colorectal cancer, the role of hypoxia, and the advances in antiangiogenic therapy. Last, the use of circulating angiogenic growth factors in ⁹⁰Y-radioembolization was reviewed. Two literature searches were conducted. A search query in PubMed on angiogenesis in colorectal cancer, and a systematic search in PubMed (Medline), Embase, and the Cochrane Library (October 2018) with synonyms for “radioembolization” and “angiogenic growth factor.” The first search yielded 3 relevant publications on the role of angiogenic growth factors in colorectal cancer, hypoxia, and antiangiogenic therapy. The second search yielded two prospective studies on circulating angiogenic factors and their relationship with response and survival after ⁹⁰Y-radioembolization for colorectal cancer liver metastases. Rises in circulating angiogenic growth factors after radioembolization were seen in both studies. High baseline values of Ang-2 and IL-8 correlated with shorter survival and post ⁹⁰Y-radiembolization rises in Ang-2 and HGF correlated with early progression. Various angiogenic growth factors play a role in the development and progression of colorectal cancer. Several factors show correlation with poor outcomes after ⁹⁰Y-radioembolization and might be used for patient selection in the future, however, validation in larger comparative studies is required.