CA: A Cancer Journal for Clinicians, Vol 25, 198-203, Copyright
© 1975 by American Cancer Society
BCG in the Treatment of Human Cancer
William D. Terry M.D.1
1 Associate Director for Immunology, Division of Cancer Biology and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
BCG is one of a large number of agents under study as possible immunostimulants and, in turn, represents only a small segment of the rapidly developing field of immunotherapy. By and large, immunotherapy is now and will continue to be used as part of the combined modality approach to cancer treatment. Immunotherapists are working closely with surgeons, radiotherapists and chemotherapists to optimize the potential benefits to the patient. However, many serious problems interfere with the immediate achievement of this goal. Chemotherapy and radiotherapy frequently have a markedly suppressive effect on immunologic function, and even surgery is followed by a period of relative immunosuppression. Detailed studies on the type and duration of immunologic reactions will be required before optimal, multimodality therapy can be designed.
For at least the next several years, clinicians must consider all forms of immunotherapy of cancer as experimental, and not as established treatments. Appropriate patients should be referred and placed as soon as possible in centers where clinical trials are in progress. To assist physicians in patient referral, an Immunotherapy Registry has been developed by the National Cancer Institute.
Results of immunotherapy trials in man and other animals have indicated that the immune system usually makes an effective response against cancer only when the tumor burden is relatively small. This necessitates that immunotherapy be studied in patients with relatively early cancers. Referring patients with early, small tumors to specialized centers assures that adequate numbers will be entered into clinical trials of BCG or other agents, helping to speed the day when immunotherapy will become an integral part of the treatment of human cancer.
