Cancer Biology

Cancer — uncontrolled cell division caused by DNA mutations — is the second leading cause of death globally (10 million annually). It is not a single disease but over 200 distinct diseases affecting different tissues, with different genetics, behaviors, and treatments. The probability of developing cancer is approximately 40% over a lifetime in developed countries. The past 20 years have seen revolutionary advances: targeted therapies (drugs hitting specific cancer mutations), immunotherapy (checkpoint inhibitors, CAR-T cell therapy — using the immune system to destroy cancer), liquid biopsies (detecting cancer from blood samples), and early screening. Childhood leukemia, which was uniformly fatal in 1970, now has 90%+ survival. Melanoma, once rapidly fatal once metastatic, now has 50% long-term survival with immunotherapy.