Kossman DA, Williams NI, Domchek SM, Kurzer MS, Stopfer JE, Schmitz KH. Exercise lowers estrogen and progesterone levels in premenopausal women at high risk of breast cancer. J Appl Physiol 111: 1687-1693, 2011. First published September 8, 2011 doi:10.1152/japplphysiol.00319.2011.-Experimental and clinical data support a role for estrogens in the development and growth of breast cancer, and lowered estrogen exposure reduces breast cancer recurrence and new diagnoses in high-risk women. There is varied evidence that increased physical activity is associated with breast cancer risk reduction in both pre-and postmenopausal women, perhaps via lowered estrogen levels. The purpose of this study was to assess whether exercise intervention in premenopausal women at increased breast cancer risk reduces estrogen or progesterone levels. Seven healthy premenopausal women at high risk for breast cancer completed a seven-menstrual-cycle study. The study began with two preintervention cycles of baseline measurement of hormone levels via daily first-morning urine collection, allowing calculation of average area under the curve (AUC) hormone exposure across the menstrual cycle. Participants then began five cycles of exercise training to a maintenance level of 300 min per week at 80 -85% of maximal aerobic capacity. During the last two exercise cycles, urinary estradiol and progesterone levels were again measured daily. Total estrogen exposure declined by 18.9% and total progesterone exposure by 23.7%. The declines were mostly due to decreased luteal phase levels, although menstrual cycle and luteal phase lengths were unchanged. The study demonstrated the feasibility of daily urine samples and AUC measurement to assess hormone exposure in experimental studies of the impact of interventions on ovarian hormones. The results suggest value in exercise interventions to reduce hormone levels in high-risk women with few side effects and the potential for incremental benefits to surgical or pharmacologic interventions. menstrual cycle; BRCA1/2 mutation carriers EXPERIMENTAL AND CLINICAL data support a role for estrogens in the development and growth of breast cancer, with the primary hypothesis being that estrogens interact with receptors in a manner that increases cell proliferation rates (7, 70). Lowering endogenous estrogen levels via bilateral oopherectomy or blocking estrogen effects with selective estrogen receptor modulators such as tamoxifen and raloxifene reduce the rate of initial diagnoses among women at high risk of developing breast cancer (11,29,38,34,36,55). Early onset of menarche, late first full-term pregnancy, and late menopause, factors that increase lifetime estrogen exposure, have all been associated with higher rates of breast cancer. On the other hand, there is conflicting epidemiologic evidence of a link between premenopausal endogenous estrogens and breast cancer risk. Of seven studies identified, four observed a significant inverse association of endogenous estrogens with breast cancer risk in premenopausal w...
INTRODUCTION:A high proportion of patients with metastatic prostate cancer (mPC) have bone metastases (BM) which are associated with a high level of morbidity, including bone pain and skeletal related events. Although the epidemiology of prostate cancer is well documented in the United Kingdom, data on the stage at diagnosis, survival of metastatic cancer and data on incidence / prevalence of BM subsequent to prostate cancer are surprisingly scarce for such a common disease. OBJECTIVES: To develop a disease model to estimate the number of men with BM due to PC in the UK from 2010 to 2020. METHODS: A four-stage disease model (non-mPC, mPC, death from PC, death-other causes), simulating the progression of PC was developed to estimate the incidence and prevalence of mPC and BM in the United Kingdom. The incidence-based model was run over 50 years to obtain incidence and prevalence data. A 1-year cycle length was used. Inputs were obtained from published official sources. Validation used UK national statistics on number of cases / deaths with PC. After validation, a BM-component was fitted within the PC model to ensure consistency with the UK national statistics and obtain estimates of the future incidence and prevalence of BM in the United Kingdom. RESULTS: The model estimated an increase in new patients with PC from 2006 to 2020 from 35,510 to 47,417. mPC patients will increase from ϳ20,000 (1990) to 66,100 (2020). Assuming a 30% prevalence of BM and a RR of 1.35 for survival with BM compared to visceral metastases, the number of PC diagnosed men living with BM ranges from 6,000 (1995) to ϳ16,200 (2020). CONCLUSIONS: This disease model shows that the prevalence of PC is expected to increase in the UK. A substantial number of patients with mPC will develop BM though this is expected to be stable.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.