Antitumor immunotherapy – now for the elderly

Cancer affects older people more often, and their bodies, as a rule, resist the disease worse and do not tolerate the toxic side effects of treatment. However, the results obtained by researchers from the University of Texas, working under the guidance of Professor Tyler Curiel, indicate that certain types of immunotherapy, previously considered effective only against young patients, can also be used to treat elderly patients, provided they adapt to age-related changes in the immune system.

As the organs age, they wear out. They continue to perform their functions, but the quality of their work is deteriorating. The immune system of an aging organism also weakens, but this process is accompanied by certain changes that affect the nature of developing immune reactions.

Cancer immunotherapy, the purpose of which is to remove regulatory T-lymphocytes that suppress the immune response and, accordingly, contribute to the progression of cancer. In the body of cancer patients, the number of such cells is usually increased. In the treatment of young patients, the drug suppressing the activity of regulatory T-lymphocytes ensures better functioning of the immune system. At the same time, in elderly patients, even despite the suppression of the activity of these cells, the drug does not have a clinical effect.

Curiel and his colleagues have found an explanation for this phenomenon. They found that in the body of old mice, when the activity of regulatory T-lymphocytes is suppressed, another type of immune cells, myeloid suppressor cells, multiply. This neutralizes the therapeutic effect of the drug. In the body of young animals, nothing like this is observed.

When a second drug suppressing the activity of myeloid suppressor cells was added to the therapy protocol, the immune system of old animals began to work as well as the immune system of young mice, while no changes were observed in the latter.

These results were obtained in experiments on animals with melanoma. Checking the revealed pattern on a mouse model of colon cancer, which is one of the main causes of death in elderly people, showed that in this case, other suppressor cells replace regulatory T-lymphocytes. However, they managed to get rid of them by selecting the right combination of drugs.

According to the researchers, at first glance, their proposed approach looks complicated, but it will allow selecting specific treatment methods that are easier for patients to tolerate than traditional chemotherapy. The next stage for which the Curiel group is preparing is to conduct clinical trials involving elderly cancer patients.

Article by Vincent Hurez et al. Mitigating Age-Related Immune Dysfunction Heightens the Efficacy of Tumor Immunotherapy in Aged Mice published in the journal Cancer Research.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Medical Xpress materials:
Immunotherapy for elderly cancer patients finds new promise in drug combination.

17.04.2012