Published online Aug 8, 2015. doi: 10.4254/wjh.v7.i16.2029
Peer-review started: July 30, 2014
First decision: December 17, 2014
Revised: July 21, 2015
Accepted: July 24, 2015
Article in press: July 27, 2015
Published online: August 8, 2015
Processing time: 375 Days and 2.1 Hours
The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma (HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide.
Core tip: Antiangiogenic therapy has become an important component of treatment in hepatocellular carcinoma (HCC) patients. However, traditional anatomic imaging of tumor shrinkage is not appropriate to evaluate the efficacy of antiangiogenesis achieved by normalizing tumor vasculature and systemic suppression of angiogenic and inflammatory cytokines. To identify and validate potential response biomarkers, standardized systemic, circulating, tissue and imaging assays should be incorporated in to preclinical and clinical studies regarding the combination of antiangiogenic agents to cytotoxic or biologic agents. The optimal dosage, schedule and duration of antiangiogenic during combination therapy for HCC patients should be titrated according to these response biomarkers.