Writen by mr. Voulgaris Evangelos, Pathological Oncologist, Scientific Head of the Oncology and Chemotherapy Department of ANASSA Clinic
For the first time, a study has shown that exercise can have a direct biological effect on the tumour microenvironment of breast cancer patients. The Pre-Operative Health and Body (PreHAB) study, published May 23, 2019 in the journal Clinical Cancer Research, provides further insight into the already well-known observation by oncologists that breast cancer patients who exercise have better survival compared to those who do not exercise. A 2014 observational study had shown that women who had the highest levels of physical activity after a breast cancer diagnosis had a 29% lower risk of breast cancer mortality and a 43% lower risk of all-cause death compared to patients who did not exercise. Until today, however, we have had no direct evidence that exercise per se is helpful for our patients by reducing their risk of dying from cancer.
The team that published the study tried to see if there was a biological basis to what we see in observational studies, and this is the first study to show that exercise before surgery can cause changes in the tumour microenvironment in women with newly diagnosed breast cancer. The findings are similar to what has been observed in experimental animals, which gives the findings greater validity.
The 27 women who participated received psychological support to increase their physical activity to 220 minutes of exercise per week (40 minutes of strength training and 180 minutes of moderate-intensity aerobic exercise). Another group of 22 women was used as a control group. The control group was only given psychological support as part of the preoperative preparation. At the start of the study, women in both groups reported no regular exercise. The intervention lasted approximately 30 days and the patients were taken to surgery. After surgery, preoperative and postoperative biopsy specimens were compared in 32 patients, 16 from each group.
What was observed in patients who underwent an exercise programme before surgery was a mobilisation of the body’s defence system against the tumour cancer cells. This effect was not observed in the group that did not exercise.
Whether longer or more intensive exercise would have a greater effect on the tumour is difficult to measure, especially because women with newly diagnosed breast cancer must undergo surgery in time. However, the highly beneficial effects of exercise on both breast cancer-associated and all-cause mortality found in the observational studies primarily involved brisk walking as the main exercise intervention, suggesting that more intensive exercise may not have a greater impact on breast tumours.
This is a hypothesis-generating study, and while it is exciting to see some immediate effects of exercise on breast tumors, we need to understand what the next step in research in this area will be. So a second, larger trial is planned to try to replicate the findings in a larger group of patients.
Clin Cancer Res. Published online May 23, 2019
