Immunotherapy, medicine’s latest fad, holds that you can fight cancer by giving help to the immune system. Behind this theory is the belief that the immune system has a built in mechanism for fighting cancer, just as it fights infections. However, no one has been able to find foreign antigens (foreign proteins) in tumour cells. Unlike infectious viruses, tumour cells have the same antigens as normal cells, so the immune system cannot recognize tumours as different in order to destroy them.
Some of the treatments centre around interleukin 2, or IL-2, a growth factor which is cultured with a patient’s lymphocytes, to transform them into killer cells. This is mainly being tried out on kidney and skin cancer patients, with little success (The Immortal Cell, Dr Gerald Dermer, Avery, Garden City Park, New York, 1994).One study of colorectal cancer patients given a “vaccine” against tumour cells appeared to prove beneficial, until the study was investigated by the Committee on Government Operations of the US House of Representatives and found to be unreliable (The Immortal Cell).
Researchers are attempting to use heat shock proteins (HSPs) to develop vaccines that offer new opportunities for cancer immunotherapy. Pramod Srivastava, Professor of Immunology in the biological sciences department at Fordham University in New York’s Bronx, has been studying the mechanism by which HSPs help bolster the immune system. Produced by almost every cell in the body under normal conditions, HSPs increase in number when cells encounter stress, such as a sudden increase in temperature. (JAMA, 1995; 274: 4; 291).
However, a generation of research and development has yet to yield an effective immunotherapy for cancer. And, like chemotherapy, the latest immunotherapy regimens make patients extremely sick, so it’s considered for only a selected handful of the healthiest patients.