T cells become more effective weeks after chemotherapy ends in cancer survivors who exercise
Recent study findings may clarify the reasons why exercise can significantly reduce the likelihood of secondary cancers in survivors. A preliminary study indicates that when cancer survivors exercise for several weeks after completing chemotherapy, their immune systems become more responsive and can potentially lower future cancer occurrences.
According to study leader Laura Bilek, previous research shows a range of positive links between exercise and cancer. For example, exercise can reduce the risk of initial incidences of several different types of cancers, and it can decrease the risk of recurrence and secondary cancers among survivors of some types of cancers. However, further investigation of the mechanism behind these associations was needed.
Based on other research suggesting that exercise can remodel the immune system, Bilek, Graham Sharp, and Geoffrey Thiele, all of the University of Nebraska Medical Center, and Daniel Shackelford, Colin Quinn, and Carole Schneider, all of Rocky Mountain Cancer Rehabilitation Institute, analyzed T cells in the blood of cancer survivors before and after a 12-week exercise program. The researchers analyzed a group of 16 cancer survivors, 15 of whom had recently concluded chemotherapy treatment. Following the 12-week exercise program, study results showed a significant number of the patients’ immune cells converted from a senescent form to a naive form and were prepared to fight cancer and infections.
For the study, researchers first took blood samples from each of the volunteers to determine the number of senescent and naive T cells in each patient. Then, study subjects participated in 12-week exercise programs at the Rocky Mountain Cancer Rehabilitation Institute. All programs were customized for the participants and combined elements of cardiovascular exercise, strength and endurance training, and exercises for flexibility, posture, and balance.
Following the 12-week program, researchers analyzed a second blood sample from each volunteer and discovered that the ratio of senescent to naive T cells changed favorably in the majority of participants. In fact, most of the study subjects regained greater numbers of the naive variety.
“What we’re suggesting is that with exercise, you might be getting rid of T cells that aren’t helpful and making room for T cells that might be helpful,” Bilek says.
Source: American Physiological Society.