Introduction to Cancer Immunotherapy

Cancer is a complex illness characterized by the transformation of healthy cells into cancerous ones, with origins that may be chemical, biological, or radiological. Various triggers, such as aberrant biological pathways or DNA mutations, can lead to this transformation. The altered genetic makeup of these cells results in abnormal protein synthesis and disrupts normal cellular functions. Treatments like chemotherapy, radiation therapy, and hormonal therapy, while targeting cancer cells, come with their own set of side effects due to their nonspecific nature. Chemotherapy’s effectiveness relies on targeting rapidly dividing cancer cells. Historically, there have been accounts of tumors spontaneously disappearing, sometimes following feverish or viral episodes, indicating the body’s intrinsic ability to combat cancer. While uncommon, untreated malignant tumors can regress spontaneously. Immunosuppression is known to heighten cancer risk, emphasizing the crucial role of the immune system in cancer defense. The use of live, attenuated Bacillus Calmette-Guérin bacteria to treat bladder cancer since 1976 has become the standard of care. Effective cancer immunity relies on complex interactions between the tumor, the host, and the environment. Evidence suggests a strong correlation between immune system dysfunction and cancer development.