Abstract B066: Changes in circulating immune profile in cancer patients during and after acute exercise

Abstract Background: Exercise reduces tumor growth in some mouse models through immunomodulation. However, little is known how immune system responds to exercise in different cancer patients. Here, the aim was to compare immunological responses to 10-minute and 30-minute acute exercise in cancer patients as well as to compare responses between lymphoma and breast cancer patients. Methods: Participants were 15 lymphoma patients (mean (SD) age 59 (17) years) and 29 breast cancer patients (57 (10) years) who had not yet started their cancer treatments. Half of the patients performed a 10-minute exercise and the other half a 30-minute exercise on bicycle ergometer. Venous blood samples were drawn at baseline, during the exercise, and 30 minutes after the exercise. Immune cell subsets were analyzed using flow cytometry and the level of 27 cancer-specific cytokines were analyzed with multiplex cytokine assay. Results: Acute exercise increased the number of circulating total leukocytes, neutrophils, lymphocytes, monocytes, eosinophils, basophils, CD4+ T cells, T helper (Th) 1 cells, Th 2 cells, Th17 cells, regulatory T cells, CD8+ T cells, CD4-CD8- T cells, CD19+ B cells, and CD56+ natural killer (NK) cells in cancer patients. Further, acute exercise increased the level of Eotaxin and IP-10 and decreased the level of interleukin (IL) 9, PDGF-BB, MIP-1α, MIP-1β, and TNF-α. The mobilization of CD4+ T cells, CD8+ T cells, CD4-CD8- T cells, CD19+ B cells, and CD56+ NK cells was greater during a 30-min exercise compared to a 10-min exercise. Further, Eotaxin and IP-10 levels increased significantly more during a 30-min exercise. After adjustment with exercise intensity, mobilization of monocytes, basophils, and Th 2 cells was significantly different between breast cancer and lymphoma patients, with increases being greater in breast cancer patients. Moreover, changes in IL-4 and IL-13 levels were significantly different between breast cancer and lymphoma patients. IL-4 level increased during exercise in breast cancer patients, but remained unchanged in lymphoma patients. IL-13 level increased 30 min post-exercise in lymphoma patients and decreased slightly in breast cancer patients. Conclusions: Acute exercise is a strong stimulus for mobilizing immune cells in cancer patients which can have positive effects for the patients. The longer the exercise, the more cytotoxic immune cells are increased. However, exercise also increases the level of immune cells and cytokines that can have pro-tumorigenic effects. Altogether, exercise-induced changes in immune profile are fairly similar in breast cancer and lymphoma patients. Further investigation is needed to see whether these immunological changes in the circulation impact tumor microenvironment and affect tumor growth as seen in mouse models. Citation Format: Tiia Koivula, Jooa Norha, Maija Hollmèn, Eeva Juhanoja, Salla Lempiäinen, Carl Johan Sundberg, Heikki Minn, Helene Rundqvist, Petteri Rinne, Ilkka Heinonen. Changes in circulating immune profile in cancer patients during and after acute exercise [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr B066.