As an expert in the field of oncology, I can provide a detailed explanation of the impact cancer has on the body. Cancer is a complex disease characterized by the uncontrolled growth and division of cells. This can occur when the body's normal regulatory mechanisms fail, leading to the accumulation of old cells that do not die and the formation of new, abnormal cells. The impact of cancer on the body is multifaceted and can vary depending on the type and stage of the cancer. 1. Tumor Formation: In many types of cancer, the abnormal cells can group together to form a mass known as a tumor. Tumors can be benign (non-cancerous) or malignant (cancerous). Malignant tumors can invade surrounding tissues and organs, disrupting their normal function. 2. Metastasis: One of the most dangerous aspects of cancer is its ability to spread to other parts of the body through a process called metastasis. This occurs when cancer cells break away from the original tumor, enter the bloodstream or lymphatic system, and form new tumors in distant organs. 3. Systemic Effects: Cancer can have widespread effects on the body, including fatigue, weight loss, and a weakened immune system. These systemic effects can be caused by the cancer itself, the tumor's impact on normal body functions, or the body's response to the cancer. 4. Organ Dysfunction: As tumors grow, they can press on vital organs, causing pain and potentially leading to organ dysfunction or failure. 5. Nutritional Deficiencies: Cancer and its treatment can lead to malnutrition and nutritional deficiencies, as the cancer's growth can outpace the body's ability to supply nutrients. 6. Psychological Impact: The diagnosis and treatment of cancer can have a profound psychological impact on patients, leading to stress, anxiety, and depression. 7. Treatment Side Effects: Cancer treatments, such as chemotherapy and radiation, can have significant side effects, including nausea, hair loss, and damage to healthy cells and tissues. read more >>

Cancer develops when the body's normal control mechanism stops working. Old cells do not die and cells grow out of control, forming new, abnormal cells. These extra cells may form a mass of tissue, called a tumor. Some cancers, such as leukemia, do not form tumors.read more >>