Although the few published preclinical studies suggest a potential role for P2Y12 antagonists in chemoprevention and/or in potentiating the effect of cytotoxic drugs (Sarangi et al., 2013; Dasari and Tchounwou, 2014; Pandey et al., 2014) there are no results from randomized clinical trials (RCTs) aimed to assess the effects of these drugs on cancer and metastasis.