Targetable pathways for drug repurposing in gastric cancer

Gastric cancer (GC) is both the fifth most common cancer worldwide and the fifth in mortality. Owing to a lack of symptoms in the early stages and unspecific clinical presentation in the later stages, GC is usually diagnosed at advanced stages. This means that only approximately 60% of patients are eligible for curative treatment, and overall, GC patients have a 5-year survival rate of only 28.3%, underscoring the importance of developing new treatment strategies. Drug repurposing involves identifying new therapeutic uses for approved drugs and is a promising strategy for cancer treatment because of its lower cost and faster development time. A variety of targetable pathways are involved in GC progression, including the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, p53, Janus kinase 2/signal transducer and activator of transcription 3, hypoxia-inducible factor-1α, wingless-type mouse mammary tumor virus integration site family/beta-catenin (Wnt/β-catenin), nuclear factor kappa B, and Hippo pathways. Therefore, the repurposing of drugs targeting these pathways represents an interesting option in the search for new treatments for GC. In this review, we explore some relevant pathways involved in the development of GC and the possibilities of repurposing drugs that target them.