Normal cells grow, divide and die all according to an intracellular program and in response to external signals. When cells transform into cancerous cells, they divide uncontrollably, do not die when they should, damage the surrounding normal tissue, and have the potential to spread to other tissues and organs. When the cancerous cells divide locally, they form a mass called a cancerous, or malignant, tumor. The three main types of treatment for cancer are surgery, radiation therapy and chemotherapy.
Surgery
The American Cancer Society reports that surgery is the oldest type of cancerous tumor treatment. Surgery is used to physically remove the cancer, and also aids in the determination the stage of cancer growth. By examining the tissues surrounding the cancerous tumor, the surgeon can determine how far the cancer has spread. If the doctor finds that the cancer is localized to one tumor, the cancer is in the earlier stages of growth. In contrast, if the surgeon finds that the cancer has spread significantly to other tissues and/or organs, the cancer is at an advanced stage of growth.
Cancer surgery can be classified into several different subtypes. The goal of curative surgery is to remove all of the cancerous tissue. Debulking surgery drastically reduces the amount of tumor present, acknowledging that all of the cancer cannot be removed. Preventative surgery removes tissue that is likely to become cancerous, such as for women who have mutations in the BRCA1 or BRCA2 breast cancer genes.
Chemotherapy
Chemotherapy is a type of cancer treatment in which chemicals are used to kill the cancer cells. Oncolink, a cancer resource sponsored by the Abramson Cancer Center of the University of Pennsylvania, notes that chemotherapy was first used in the early 190's. They add that chemotherapy kills cancer, but also can kill normal cells in the body. Thus, the goal of chemotherapy is to kill as much of the cancer as possible, but with the least side effects.
One chemotherapeutic strategy is to target fast-growing cells, which is a general feature of cancer cells. Other fast-growing cells in the body are located in hair follicles and the lining of the stomach, which are also often killed by chemotherapeutic agents. This is why people undergoing chemotherapy often lose their hair, have a reduced appetite, and experience nausea and vomiting.
Radiation Therapy
Radiation therapy kills cancer cells with high-energy radiation waves. The Stanford Cancer Center notes that there are different types of radiation therapy used for cancer treatment. Two common types are stereotactic radiation therapy and brachytherapy. Stereotactic radiation therapy combines radiation therapy and computerized imaging to focus the radiation as much as possible on the cancerous tumor, but not on the surrounding healthy tissue.
Brachytherapy involves placing a radiation source inside the tumor within the body. Depending on the desired radiation dose, the source is placed in the tumor temporarily or placed within the tumor for a certain time period, and then removed.
