JAMA: Effects of postmenopausal hormone intervention on breast cancer morbidity and mortality in women.

Researchers recently looked at the effects of menopausal hormone therapy on breast cancer morbidity and mortality.
this long-term follow-up controlled randomized clinical trial involving 27,347 postmenopausal women between the ages of 50 and 79, with a history of breast cancer and a negative baseline breast cancer X-ray screening.
participants were recruited from 1993 to 1998, followed by a follow-up from December 31, 2017.
for 16,608 participants who had not had a hysterectomy, 8506 were randomly given 0.625 mg/day of combined estrogen (CEE) combined with 2.5 mg/day of acexyprogeprosterone (MPA), and 8102 received a placebo.
of 10,739 hysterectomy patients, 5310 received 0.625 milligrams/day of CEE treatment alone and 5,429 received a placebo. the median duration of the ceE-MPA intervention was 5.6 years
, and the median duration of CEE single drug intervention was 7.2 years.
the main result of the study was the incidence of breast cancer, and the secondary result was breast cancer death. the baseline age of
participants was 63.4 years.
of 10,739 hysterectomy participants, pure CEE treatment was associated with a reduced incidence of breast cancer compared to placebo: 238 (annualized rate of 0.30%) vs 296 cases (annualized rate of 0.37%; risk 0.78 per cent compared to (HR) and associated with a decrease in breast cancer mortality: 30 deaths (annualized mortality rate of 0.031%) vs 46 deaths (annual mortality rate of 0.046%; HR: 0.60).
, for 16,608 women without hysterectomy, CEE-MPA treatment led to a significant increase in breast cancer incidence, with 584 cases (annualized rate of 0.45%) vs 447 cases (annualized rate of 0.36%; HR: 1.28), but not significantly related to breast cancer mortality: 71 (annualized mortality rate of 0.045%) 53 deaths (annual mortality rate of 0.035%;
long-term follow-up findings found that for postmenopausal women with hysterectomy, receiving a combination of estrogen reduced breast cancer incidence and mortality, but for participants who retained the uterus, hormone intervention increased the incidence of breast cancer.
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