The use of<unk>  is still of limited use and requires further evaluation. Currently, most of the clinical studies are phase I and II trials. There are only about ten studies which have proceeded to phase III. Heterogeneity of studies The studies are heterogeneous in terms of patient selection, chemotherapeutic agents, dosage and dosing interval. Correspondingly, the clinical outcomes are variable. Multiple reviews pointed out that further studies should be carried out to determine the most effective drugs, dosage and dosing interval according to tumor and patient characteristics. Lack of promising biomarkers Different biomarkers for monitoring the patients’ response towards<unk>  have been tested, but the results showed that the biomarkers did not correlate well with the treatment response. Without proper biomarkers, it is difficult to determine the optimal<unk>  dose for the patients. Blood biomarkers related to angiogenesis, such as VEGF, TSP-1, circulating endothelial cells (CECs) and CEPs, have been tested. It was reviewed that most studies did not show a significant correlation between the level of these biomarkers and the treatment response, in terms of clinical outcomes such as overall survival and progression-free survival. This is likely due to the complex interplay of factors in angiogenesis. Besides blood biomarkers, an imaging called dynamic contrast-enhanced MRI (DCE-MRI) has also been used. It assesses the tumor vascularity by measuring blood flow, fractional intravascular volume and other related parameters. However, as it only selects one or two portions of the tumor for measurement, it may not represent the overall vascularity and predict the response. Biomarkers related to the immunomodulatory effects of<unk>  are also under investigation. The most commonly studied one is Tregs. With advances in technologies, not only the number of Tregs but also other properties such as receptor profile and functioning of Tregs can be studied, which may aid in finding more suitable biomarkers in the future.
Metronomic therapy
Destination therapy
Breakthrough therapy
Multisystemic therapy
Dose-dense chemotherapy
Carboxytherapy
Proton therapy
Salvage therapy