There are many forms of palliation which physicians employ to help patients whose disease has progressed beyond the stage which permits a cure. Due to limitations of space we will mention only a few of those most commonly used.

Chemotherapy

Some forms of malignant disease are treated by the administration of chemicals. The objective of this type of therapy is to destroy the cancer without injury to the patient. Interest in chemotherapy is increasing not only because of the tremendous potential now offered in terms of palliative therapy, but because there are many who feel that someday chemotherapy will rank as a curative agent. Recently there have been some promising leads in this direction.

Among the drugs of greatest clinical value in cancer chemotherapy are the nitrogen mustard compounds, mechlorethamine and triethylene melamine: the folic acid antagonists, a-methopterin (methotrexate) and aminopterin; the purine analog, 6-mercapto-purine. See appendix III.

Many of these agents cause serious toxic manifestations, particularly to the hematopoietic system. For this reason the patient is often hospitalized during therapy. However, it is possible to administer chemotherapeutic agents to nonhospitalized patients who are able to report frequently for the studies which are necessary to determine individual responses to the drugs. Many of these drugs offer worthwhile benefits in terms of providing remissions of disease for varying lengths of time.

Chemotherapeutic agents may be given in a variety of ways- by mouth, by vein (directly or by infusion), by injection or by artery. A newer method for introducing chemotherapeutic agents into selected body sites is called perfusion. This procedure is being studied in certain specialty hospitals and research centers. The technique consists of isolating the affected body part by tourniquet and introducing prepared solutions of the drug through the arteries. For example, widely disseminated melanoma in an arm or leg may be treated by isolating the limb and perfusing the affected area with the chemotherapeutic agent of choice (nitrogen mustard, methotrexate, etc.).

Under the leadership of the U.S. Public Health Service a national cooperative chemotherapy program is being conducted throughout the United States. In addition to the Government this program involves universities, medical schools, and pharmaceutical industries. Cooperating agencies are concerned with the screening of promising compounds, the clinical trial of drugs, and the use of drugs in combination with radiation and surgery. This is an attempt to focus a concerted countrywide effort on the chemotherapeutic approach to cancer therapy.

Surgical Procedures

A wide range of surgical procedures can be called upon to achieve palliation for those for whom cure is not possible. For some patients the only result may be the increased comfort which ensues, but for others, remission of the disease may occur, or life may be prolonged. Examples of palliative therapy include the neurological procedures for relief of pain, (rhizotomy, chordotomy, etc.) simple mastectomy for large ulcerating lesions of the breast, colostomy to relieve obstruction, etc.

The so-called "ablative procedures" for carcinoma of the breast and prostate are also forms of palliative therapy. This type of surgery seeks to remove certain hormone sources in the body which influence the development of cancer. Ovariectomy, adrenalectomy, and hypophysectomy for cancer of the breast, and orchidectomy and adrenalectomy for carcinoma of the prostate offer some hope of temporarily halting progress of the disease.

Radiation Therapy

Radiation therapy is used palliatively to treat a wide gamut of tumors. For example, X-ray treatment is used for advanced lung cancer, Hodgkin's Disease, multiple myeloma, and cancer of the breast. Solid sources of radiation such as cobalt or radium are sometimes used.

Liquid radioisotopes also have their place in palliative therapy. They do not cure the patient, but are helpful in arresting progress of the disease. Those commonly used for therapy include radioactive iodine (I131) for cancer of the thyroid; radioactive gold (Au198) for prostatic malignancies or as a palliative measure to decrease ascites and pleural effusion; radioactive phosphorus (P32) to treat leukemia or in the form of chromic phosphate for ascites and pleural effusion.

A radioactive chemical acts in the body in the same way in which the chemical would act if it were not radioactive. For example, radioactive iodine locates in the thyroid gland in the same way as nonradioactive iodine. This makes it possible to treat thyroid cancer by giving the patient a dose of radioactive iodine which will locate in the thyroid gland and cause tumor destruction. Under some conditions the iodine will also be picked up by metastases.

The amount of a radioisotope given for treatment is considerably higher than that given for diagnostic purposes. Therapy doses are measured in millicuries (1/1000 of a gram) whereas diagnostic doses are measured in microcuries, amounts which are minute in comparison (see page 61).

Hormone Therapy

Hormones are chemicals liberated by the endocrine glands of the body. Many cancers occur in tissues influenced by hormones-for example, cancer of the breast, prostate, and uterus. By utilizing hormones to change the hormone environment in which the tumor is functioning it is sometimes possible to arrest the course of disease for varying periods of time. Many patients with cancer of the breast respond to estrogen or androgen therapy, and may even enjoy a remission of quite long duration before other forms of treatment become necessary. Unfortunately all tumors of the breast do not respond equally well, and much remains to be learned about hormone therapy in general.