ContextPhysical activity has been shown to decrease the incidence of breast
cancer, but the effect on recurrence or survival after a breast cancer diagnosis
is not known.ObjectiveTo determine whether physical activity among women with breast cancer
decreases their risk of death from breast cancer compared with more sedentary
women.Design, Setting, and ParticipantsProspective observational study based on responses from 2987 female
registered nurses in the Nurses’ Health Study who were diagnosed with
stage I, II, or III breast cancer between 1984 and 1998 and who were followed
up until death or June 2002, whichever came first.Main Outcome MeasureBreast cancer mortality risk according to physical activity category
(<3, 3-8.9, 9-14.9, 15-23.9, or ≥24 metabolic equivalent task [MET]
hours per week).ResultsCompared with women who engaged in less than 3 MET-hours per week of
physical activity, the adjusted relative risk (RR) of death from breast cancer
was 0.80 (95% confidence interval [CI], 0.60-1.06) for 3 to 8.9 MET-hours
per week; 0.50 (95% CI, 0.31-0.82) for 9 to 14.9 MET-hours per week; 0.56
(95% CI, 0.38-0.84) for 15 to 23.9 MET-hours per week; and 0.60 (95% CI, 0.40-0.89)
for 24 or more MET-hours per week (P for trend =
.004). Three MET-hours is equivalent to walking at average pace of 2 to 2.9
mph for 1 hour. The benefit of physical activity was particularly apparent
among women with hormone-responsive tumors. The RR of breast cancer death
for women with hormone-responsive tumors who engaged in 9 or more MET-hours
per week of activity compared with women with hormone-responsive tumors who
engaged in less than 9 MET-hours per week was 0.50 (95% CI, 0.34-0.74). Compared
with women who engaged in less than 3 MET-hours per week of activity, the
absolute unadjusted mortality risk reduction was 6% at 10 years for women
who engaged in 9 or more MET-hours per week.ConclusionsPhysical activity after a breast cancer diagnosis may reduce the risk
of death from this disease. The greatest benefit occurred in women who performed
the equivalent of walking 3 to 5 hours per week at an average pace, with little
evidence of a correlation between increased benefit and greater energy expenditure.
Women with breast cancer who follow US physical activity recommendations may
improve their survival.

https://jamanetwork.com/journals/jama/articlepdf/200955/JOC50040.pdf

Physical activity and survival after breast cancer diagnosis

0.80 (95% confidence interval [CI], 0.60-1.06) for 3 to 8.9 MET-hours per week; 0.50 (95% CI, 0.31-0.82) for 9 to 14.9 MET-hours per week; 0.56 (95% CI, 0.38-0.84) for 15 to 23.9 MET-hours per week; and 0.60 (95% CI, 0.40-0.89) for 24 or more METhours per week (P for trend = .004). Three MET-hours is equivalent to walking at average pace of 2 to 2.9 mph for 1 hour. The benefit of physical activity was particularly apparent among women with hormone-responsive tumors. The RR of breast cancer death for women with hormone-responsive tumors who engaged in 9 or more METhours per week of activity compared with women with hormone-responsive tumors who engaged in less than 9 MET-hours per week was 0.50 (95% CI, 0.34-0.74). Compared with women who engaged in less than 3 MET-hours per week of activity, the absolute unadjusted mortality risk reduction was 6% at 10 years for women who engaged in 9 or more MET-hours per week.

http://www.breastcancerpartner.com/Michelle%20Holmes%20Physical.activity.%26.brca.survival%5B1%5D.pdf

In the United States, ovarian cancer is the fourth most frequent cause of cancer death among women, following lung, breast, and colorectal cancers. Each year, approximately 26,000 women are diagnosed with ovarian cancer and 14,000 die of it. Germline mutations in BRCA1, BRCA2, or other genes have been implicated in a small fraction of cases. However, it has been suggested that, for the great majority of patients, the risk of epithelial ovarian cancer could be related to "incessant ovulation" (i.e., to the chronically repeated formation of stromal epithelial clefts and inclusion cysts following ovulation) or to some type of hormonal stimulation of ovarian epithelial cells, either on the surface of the ovary or within ovarian inclusion cysts, possibly mediated through excessive gonadotropin secretion. From the evidence to date, the relative importance of these two hypotheses--incessant ovulation and gonadotropin stimulation--cannot be distinguished. While either or both may play a role in the development of ovarian cancer, it appears that an additional major factor must also be involved. The purpose of this review is to evaluate evidence for and against the incessant ovulation and gonadotropin hypotheses, as well as to consider the possibility that risk of ovarian cancer may be increased by factors associated with excess androgenic stimulation of ovarian epithelial cells and may be decreased by factors related to greater progesterone stimulation. Many features of the evidence bearing on the pathophysiology of ovarian cancer appear to support a connection with androgens and progesterone.

/pdf/hormonal-etiology-of-epithelial-ovarian-cancer-with-a-hrk3d72y43.pdf

Hormonal etiology of epithelial ovarian cancer, with a hypothesis concerning the role of androgens and progesterone.

Associations between exercise and mental well-being have been documented repeatedly over the last two decades. More recently, there has been application of exercise interventions to clinical populations diagnosed with depression, anxiety, and eating disorders with evidence of substantial benefit. Nonetheless, attention to the efficacy of exercise interventions in clinical settings has been notably absent in the psychosocial treatment literature, as have been calls for the integration of these methods within the clinical practice of psychologists. In this article, we provide a quantitative and qualitative review of these efficacy studies in clinical samples and discuss the potential mechanism of action of exercise interventions, with attention to both biological and psychosocial processes. The meta-analysis of 11 treatment outcome studies of individuals with depression yielded a very large combined effect size for the advantage of exercise over control conditions: g = 1.39 (95% CI: .89-1.88), corresponding to a d = 1.42 (95% CI: .92-1.93). Based on these findings, we encourage clinicians to consider the role of adjunctive exercise interventions in their clinical practice and we discuss issues concerning this integration.

Exercise interventions for mental health: A quantitative and qualitative review

Background Because physical activity may affect hormonal concentrations and energy balance, we decided to investigate whether everyday exercise is related to the risk of breast cancer. Methods During 1974 to 1978 and 1977 to 1983, a total of 25,624 women, 20 to 54 years of age at entry, enrolled in health surveys and answered questionnaires about leisure-time and work activity. Results During a median follow-up of 13.7 years, we identified 351 cases of invasive breast cancer among the 25,624 women in the cohort. Greater leisure-time activity was associated with a reduced risk of breast cancer, after adjustments for age, body-mass index (the weight in kilograms divided by the square of the height in meters), height, parity, and county of residence (relative risk, 0.63; 95 percent confidence interval, 0.42 to 0.95), among women who exercised regularly, as compared with sedentary women (P for trend=0.04). In regularly exercising women, the reduction in risk was greater in premenopausal women than in postmenopausal women, and greater in younger women (<45 years at study entry) than in older women (≥45 years) (relative risk, 0.38; 95 percent confidence interval, 0.19 to 0.79). In stratified analyses the risk of breast cancer was lowest in lean women (body-mass index, <22.8) who exercised at least four hours per week (relative risk, 0.28; 95 percent confidence interval, 0.11 to 0.70). The risk was also reduced with higher levels of activity at work, and again there was a more pronounced effect among premenopausal than postmenopausal women. Conclusions Physical activity during leisure time and at work is associated with a reduced risk of breast cancer.

https://www.nejm.org/doi/pdf/10.1056/NEJM199705013361801

Physical activity and the risk of breast cancer.

In 17 female recreational athletes, ovarian function was monitored using daily hormone measurements and serial ultrasound determinations. Whereas 11 out of 13 women of a control group showed estradiol (E2) maxima beyond 470 pmol/l, progesterone (P4) maxima of 19 nmol/l or more, and a luteal phase length of 9 days or more, only 10 out of 17 athletes satisfied these criteria. Six athletes showed disturbed follicular development, and one athlete showed luteal phase disturbance. Both athletes with disturbed menstrual function (n = 7) and athletes fulfilling the above-mentioned minimal criteria (n = 10) had lower E2 concentrations in all phases of the menstrual cycle (P less than 0.05). P4 concentrations were significantly decreased in the group with disturbed menstrual function (P less than 0.05). Maximal aerobic capacity in the two athlete groups was similar. Neither athlete group showed the expected increase in caloric intake compared with the sedentary controls. It is concluded that recreational running is associated with altered ovarian function. Inadequate nutritional adaptation may be a contributing factor.

Cyclic ovarian function in recreational athletes.

Dieting causes menstrual irregularities in normal weight young women through impairment of episodic luteinizing hormone secretion

Everyday eating behavior and menstrual function in young women

The influence of semistarvation-induced hyperactivity on hypothalamic serotonin metabolism.

Male Wistar rats were housed in running wheel cages and were restricted in their food intake, in order to reduce the initial body weight by 30% within 10 days. Rats increased their daily running up to distances between 7 and 11 km compared to the maximum 2.5 km in controls fed ad libitum. The hypothalamic noradrenaline (NE) turnover, as estimated by the concentration of the major metabolite MHPG, was significantly decreased in semistarved sedentary rats compared to controls. Hyperactivity resulted in marked elevation of NE turnover at all time points examined. Semistarvation-induced decreases of dopamine (DA) turnover as estimated by the concentrations of its major metabolite DOPAC, could also be compensated by hyperactivity. The circadian pattern of NE turnover parallels the pattern of running activity. MHPG levels at times of high activity were even higher than in controls fed ad libitum (p<0.01). The availability of the precursor tyrosine, as indicated by the ratio of plasma tyrosine to the large neutral amino acids, was significantly decreased in semistarvation (p<0.0001); hyperactivity caused a further decrease (p<0.001), indicating that tyrosine availability is not, under these conditions, a limiting factor for noradrenaline turnover. The combined influence of semistarvation and hyperactivity on central catecholamine turnover in the rat is discussed as an animal model for the effects of malnutrition and heavy exercise often observed in anorexia nervosa.

A. Broocks

Papers

Cyclic ovarian function in recreational athletes.

Dieting causes menstrual irregularities in normal weight young women through impairment of episodic luteinizing hormone secretion

Everyday eating behavior and menstrual function in young women

The influence of semistarvation-induced hyperactivity on hypothalamic serotonin metabolism.

Semistarvation-induced hyperactivity compensates for decreased norepinephrine and dopamine turnover in the mediobasal hypothalamus of the rat.