Given the well-recognized properties of HCQ against inflammation, it is easily intuitable that this agent could possess interesting insights into cancer treatment. Chronic intestinal inflammation predisposes to the risk of colitis-associated colorectal cancer. In vivo, HCQ was demonstrated to interfere with cancer growth at different stages of development, both preventing tumorigenesis in the early phases and inhibiting tumor growth in the late phases in mice treated with azoxymethane and dextran sodium sulfate to induce cancer. In terms of animal survival, 120 days treatment with 50 mg/kg of HCQ intraperitoneal injection (i.p.) almost restored the survival rate to pre-treatment values and reduced the size of the tumor. The therapeutic effects of HCQ may be attributed to the significant inhibition of pro-tumorigenic and pro-inflammatory cytokines, which not only limited the tumor progression by reducing inflammation of lamina propria, but also decreased the ROS production in macrophages [111]. Many others are the mechanisms by which HCQ exerts anticancer effects, mainly in synergism with conventional chemotherapic drugs, as discussed later.