The three mainstays of cancer treatment are surgery, radiotherapy and chemotherapy. Within each category, many different options are available. An individualized treatment plan is developed for each person newly diagnosed with cancer, which includes one or more of the three main cancer treatment modalities.
Surgery
Surgery is first-line therapy for many people with cancer. The intent may be curative, therapeutic or palliative. Curative-intent surgery seeks to remove the cancer in its entirety. It is commonly the treatment of choice when a tumor has not spread and can be safely removed, and the patient is in good health.
Therapeutic surgery is used to decrease the tumor burden prior to another therapy, a process called cytoreduction. As much of the cancer as possible is removed surgically so that the follow-up treatment is left with fewer cancer cells to eliminate.
Palliative surgery is used to provide symptom relief. Cancerous tumors often cause symptoms by impinging on other tissues or organs. Removing the tumor in these situations usually results in rapid relief .
Radiotherapy
Radiotherapy (or radiation therapy) typically uses gamma radiation to kill cancer cells. Protons or electrons may be used for some cancers. Radiotherapy may be used with curative or palliative intent. It is often curative for certain types of cancer that are localized and limited to a body area that can tolerate high-dose radiation. Radiotherapy may be used after surgery to eliminate any remaining cancer cells. Chemotherapy and radiotherapy are used together or sequentially to treat some cancers, the rationale being that use of two different modalities increases the chance of cure.
Palliative radiotherapy can provide symptomatic relief when cure is not possible. It effectively relieves cancer-related bone pain. It is also frequently successful in keeping brain tumors at bay, prolonging normal mental function. Radiotherapy may be used to shrink tumors that are causing troublesome symptoms.
Four forms of radiotherapy are used for cancer treatment. External beam radiation delivers gamma rays to a targeted body field. The total dose of radiation is spread over a number of days to minimize damage to normal tissues. Stereotactic radiotherapy delivers a high dose of radiation to a small target area with minimal damage to surrounding tissues. It is most often used to treat small brain tumors. Brachytherapy employs radioactive seeds or pellets, which are placed directly in the target area for a specified period and then removed. Finally, physicians sometimes use radioactive isotopes that target a specific site in the body.
Chemotherapy
Cancer chemotherapy is used with curative or palliative intent. For some cancers, chemotherapy may be the only treatment used. However, chemotherapy is often part of a larger treatment plan that may also include surgery, radiotherapy or both. Chemotherapy typically involves a combination of drugs rather than a single agent.
Chemotherapy drugs are divided into four main types. Cytotoxic drugs kill any highly active cell, which includes not only cancer cells but also many normal cells throughout the body. Great strides have been made in managing the side effects of cytotoxic chemotherapy. Nonetheless, many side effects remain, including hair loss, fatigue, anemia and susceptibility to infections.
Hormonal therapies are used to treat cancers whose growth is influenced by hormones, such as those of the breast and prostate. Biological response drugs stimulate the immune system to fight the cancer. Targeted therapies act by disrupting pathways involved in cancerous growth, progression and spread. Because these drugs specifically target cancer cells, damage to normal cells is minimized. Hence, the side effects are typically much less severe than are those experienced with cytotoxic chemotherapy.
