Lipid-based systems for colorectal cancer: advances in early diagnosis and therapeutic efficacy

Cancer is a leading cause of death worldwide. Particularly, colorectal cancer (CRC) is one of the most prevalent and deadly cancers in both men and women. The symptoms of this malignancy appear only at advanced stages; when detected, CRC has already spread to distant organs. Although several therapies are available, treatment is often not effective at advanced stages, where the estimated 5-year survival rate is about 10 %. For this reason, the investigation of new and innovative therapies for CRC management is of utmost importance. The association of chemotherapeutic drugs with delivery systems constitutes one alternative strategy to improve their therapeutic index. This approach has been applied to different pathologies, demonstrating its therapeutic potential as evidenced by several examples already in clinical use. Among lipid-based nanoplatforms, this review will focus on solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, and, in particular, liposomes. These delivery systems can protect loaded compounds from degradation or rapid metabolization, thereby improving the therapeutic index by maximizing their targetability to tumor sites, while avoiding accumulation in healthy tissues. In addition, the combination of imaging and therapeutic agents is also an important advantage of lipid-based systems. Furthermore, liposomal formulations are already in clinical use for other cancers, and several are under clinical trials for CRC treatment. Therefore, we believe that continuous progress in the nanomedicine field will contribute to improve CRC management, thus leading to higher survival rates. The present review aims to provide an updated overview of CRC and how lipid-based systems may contribute for better diagnosis and treatment of this malignancy.