Your Body's Silent Battle: Understanding Cancer as an Immune-Mediated Disease

Traditional cancer treatments, such as chemotherapy and radiation, while targeting cancerous cells, can also weaken the patient's immune response. This can occur because these treatments often fail to eliminate all cancerous cells and can impair the function of immune cells, making it harder for the immune system to recognize and destroy any remaining malignant cells. These treatments lack the specificity to target only cancer, which is why scientists are exploring ways to harness the immune system for more targeted and effective cancer therapies, such as immunotherapies that aim to boost the immune system's natural ability to fight cancer. Chemotherapy, radiation and surgery reduce the population of cancerous cells but do not provide immunological memory.

Imunosurveillance is a critical process where the immune system constantly surveys the body, identifying and eliminating abnormal cells before they can develop into tumors. When immunosurveillance is compromised, due to factors like a weakened immune system or strategies employed by cancer cells to evade detection, cancer cells can escape this surveillance and begin to grow unchecked. These evasion strategies include downregulation of antigen processing, altered expression of chemokines and cytokines, induction of apoptosis in immune cells, and suppression of immune cell function. If immunosurveillance is ineffective then the cancer will grow and eventually progress. Immunotherapies are in development to boost immunosurveillance.

Cancer cells evade the immune system through various mechanisms, including suppressing immune responses and creating a tumor microenvironment that protects them from attack. They achieve this by downregulating antigen processing and presentation, altering the expression of certain chemokines and cytokines, inducing apoptosis in immune cells, and suppressing immune cell function. This microenvironment often contains immune regulatory cells that further dampen the immune response, allowing the tumor to thrive. Understanding these mechanisms of immune evasion is crucial for developing effective immunotherapies that can overcome these defenses and enable the immune system to target and destroy cancer cells. If the tumor continues to evade the immune system it will metastasize.

William Coley was a surgeon who, in the 19th century, observed that bacterial infections could sometimes lead to the remission of cancer. This observation suggested that the immune system could be stimulated to fight the disease. Coley's work led to early attempts to use bacteria-derived toxins to treat cancer, with some success. His pioneering work was the origin of stimulating the immune system to fight cancer. Coley is known as the "Father of Immunotherapy."

Cancer immunotherapies are treatments designed to boost the immune system's ability to recognize and destroy cancer cells. Unlike traditional treatments like chemotherapy and radiation, which directly target cancer cells but can also harm healthy cells and weaken the immune system, immunotherapies aim to enhance the body's natural defenses against cancer. Cancer immunotherapies overcome immune evasion mechanisms, and create a more favorable tumor microenvironment to allow immune cells to infiltrate and destroy the tumor. Traditional methods lack the specificity to target cancer while leaving healthy tissues untouched, leading to harsh side effects. The goal of immunotherapy is to offer more targeted and less toxic treatments by harnessing the power of the immune system.