title: Endocrine therapy mediated hot flushes in breast cancer: can exercise help?
Creators: name: France, MVK
Publisher: name: Liverpool John Moores University
Year: 2019

description: Introduction: Hot flushes are a sudden, intense sensation of heat causing skin reddening, flushing and profuse sweating. Hot flushes are a side effect of endocrine therapy for breast cancer treatment; and are possibly more frequent and severe than post-menopausal hot flushes. Many breast cancer patients do not adhere to the endocrine therapy guidelines due to the frequency and severity of hot flushes, which significantly increases the risk of cancer recurrence. There are currently few treatments able to reduce the frequency and severity of hot flushes in breast cancer. Exercise training has shown promise in alleviating menopausal hot flushes. Therefore, the overall aim of this thesis was to examine subjective and physiological frequency and severity of endocrine mediated hot flushes in breast cancer patients; and determine the effectiveness of an exercise training intervention in ameliorating endocrine mediated hot flushes. Methods: Eight breast cancer patients undergoing endocrine therapy (age 53 ± 8, BMI 29 ± 6) were recruited and 16 postmenopausal women experiencing hot flushes (age 53 ± 4, BMI 29 ± 5) from a previously reported study were included. A 7-day subjective hot flush frequency and severity questionnaire was used to examine subjective frequency and severity. To measure physiological frequency and severity sweat rate, skin and cerebral blood flow were measured in the laboratory. To do this women wore a tube-lined suit, which was perfused with 34°C water followed by a passive heat stress where water temperature increased to 48°C. A hot flush was objectively defined as a transient and pronounced increase in sternal sweat rate (&gt;0.002 mg cm-2 min-1). Sweating and cutaneous vasodilatory temperature thresholds and sensitivities were identified during the passive heating. Cardiorespiratory fitness and vascular health were also measured. Breast cancer patients (n=5) then completed a progressive 16-week moderate-intensity exercise training intervention (30-60 minutes, 3-5x per week). After which, measurements were repeated. Data were analysed using t-tests and/or general linear modelling, and presented as mean (95% CI). Results: Despite similar subjective hot flush frequency (49, 58; 95%CI = -45, 26; P = 0.56) and severity (81, 125; 95%CI = -102, 13 AU; P = 0.12) in breast cancer patients and postmenopausal women, respectively breast cancer patients demonstrated attenuated sweating, skin and cerebral blood flow responses during a hot flush (P &gt; 0.05). 16 weeks of exercise training did mediate reductions in subjective hot flush frequency by 37 hot flushes per week (52, 12; 95%CI = -21, 102, P = 0.14) and severity by 68 AU (78, 27; 95%CI = -39, 166 AU; P = 0.16) but this did not reach statistical significance. Exercise training did not attenuate physiological responses to a hot flush as no differences in sweating, skin and cerebral blood flow responses occurred (P &gt; 0.05). Conclusion: These data indicate that endocrine mediated hot flushes in breast cancer are not more severe than those experienced by post-menopausal women. Exercise training has shown promise as a potential non-pharmacological treatment for endocrine mediated hot flushes in breast cancer but requires further study.