The usual forms are X rays and gamma rays. Use of radioactive elements specific for particular target organs, such as radioactive iodine specific for the thyroid gland, is effective in treating malignancies of those organs. 18 Cytotoxic chemotherapy is used as a primary treatment for some cancers, such as lymphomas and leukemias or as an addition to surgery or radiation therapy. Often a combination of cytotoxic drugs is used. Drugs that reduce side effects may be added to the treatment, such as antinausea agents.
Tamoxifen is a naturally occurring estrogen inhibitor used to prevent breast cancer recurrences.
Flutamide is sometimes used in prostate cancer to inhibit androgen uptake. Sex-hormone related drugs such as DES and tamoxifen, which may be carcinogenic under some conditions, have proven to be protective under others. Some attack the tumor itself, while others bolster the body's ability to withstand conventional chemotherapy treatment. Other new or experimental therapies include drugs that inhibit angiogenesis and photodynamic therapy, in which a patient is given a drug to make the tumor light-sensitive, after which the tumor is exposed to bright laser light. Besides treatment of the cancer itself, progress has been made in the management of the chronic pain that often accompanies cancer and in the education of patients and physicians in such techniques as biofeedback, acupuncture, and meditation and the appropriate use of narcotics and other medications.