Eleven years after the start of a new millennium characterized by amazing scientific development, the cure for cancer remains a major challenge for humanity. In this regard, scientific efforts have focused on the search for new therapeutic targets that involve specific recognition and stop the spread of cancer cells, as well as the development of new therapeutic options that show greater specificity and better therapeutic efficacy. This review includes recent published literature about new anticancer drug design using scaffolds of β-lactams, sulfonamides, quinoline, quinoxaline and natural products, and focuses on the structure-activity relationships of scaffolds that have been reported to potently inhibit cell growth of human tumor cell lines. It describes not only those synthetic or natural compounds aimed at specific molecular targets of cancer cells in vitro, but also compounds currently in clinical trials.