Effects of Exercise Therapy on Natural Killer Cell Cytotoxic Activity in Breast Cancer Patients after Curative Surgery

OBJECTIVE: Exercise may contribute to alteration in cancer in many ways. The major cell in cellular immunity to defense against cancer cell is natural killer [NK] cell. So this study is aimed to investigate the effects of exercise on NK cell cytotoxic activity (NKCA) in breast cancer patients who underwent mastectomy. METHOD: Thirty-one breast cancer patients who had undergone curative surgery were randomly assigned to an exercise group (n=16) and a non-exercise group (n=15). Exercise therapy was consisted of aerobic activity such as bicycle ergometer for 30 minutes, twice a day, five times each week for 2 weeks. The venous blood samplings were obtained on postoperative days 1, 7 and 14. NKCA was assayed by cytotoxic response against K562 cells. The venous blood samplings were obtained on postoperative days 1, 7 and 14. NKCA was assayed by cytotoxic response against K562 cells. RESULT: The baseline study did not show any statistical difference between exercise group and non-exercise group. Mean NKCA of day 7 decreased in both groups compared with that at postoperative day 1 (p<0.05). At day 14, the difference of the mean NKCA between two groups was not significant, but the mean NKCA of the exercise group without metastasis demonstrated a significant increase compared with that of the non-exercise group without metastasis (p<0.05). CONCLUSION: This study suggested that early moderate exercise had a beneficial effect on the function of NK cells in early stage of breast cancer patients after curative surgery. A further study will be needed to evaluate long-term effect of exercise on NK cell.

Effects of Sports Activity in Spinal Cord Injured Persons

OBJECTIVE: The purpose of this study is to evaluate the effects of regular sports activity on psychosocial adaptation, natural killer cell activity (NKCA) as an immunologic measure and HDL-cholesterol level as an indirect index of heart disease in chronic spinal cord injured persons. METHOD: We compared two groups. One is sports group (n=13) who has been doing regular sports activity more than three hours a week for at least one year. Another group who leads sedentary life matched age and body mass index served as a control group (n=13). For the evaluation of psychosocial adaptation, we assessed Rosenberg Self Esteem Scale as subjective measure, Craig Handicap Assessment and Reporting Technique (CHART) as objective measure and Symptom Checklist 90 Revision (SCL-90-R) as a psychologic evaluation. NKCA and serum HDL-cholesterol level were assessed. RESULTS: There was no significant difference in subjective measure and psychologic evaluation between two groups. CHART score and NKCA are significantly higher in the sports group than in the control group (p<0.05). HDL cholesterol level was increased in the sports group compared with the control group. CONCLUSION: Participating in regular sports activity improved the psychosocial adaptation and immune system in chronic spinal cord injured persons.