Estrogen replacement effectively controls hot flashes associated with biologic or treatment-associated postmenopausal states in women. The proposed mechanism of action of estrogen replacement therapy is that it ameliorates hot flashes by raising the core body temperaturesweating threshold;[Level of evidence: I] however, many women have relative or absolute contraindications to estrogen replacement. Physicians and breast cancer survivors often think there is an increased risk of breast cancer recurrence or de novo breast malignancy with hormone replacement therapies and defer hormonal management of postmenopausal symptoms. Methodologically strong data evaluating the risk of breast cancer associated with hormone replacement therapy in healthy women have been minimal, despite strong basic science considerations suggesting the possibility of such a risk.
Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.
To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective...
In May 2002, the Women's Health Initiative (WHI), a large, randomized, placebo-controlled trial of the risks and benefits of estrogen plus progestin in healthy postmenopausal women, was stopped prematurely at a mean follow-up of 5.2 years (±1.3) because of the detection of a 1.26-fold increased breast cancer risk (95% confidence interval [CI], 1.00-1.59) in women receiving hormone replacement therapy. Tumors among women in the hormone replacement therapy group were slightly larger and more advanced than in the placebo group, with a substantial and statistically significant rise in the percentage of abnormal mammograms at first annual screening; such a rise might hinder breast cancer diagnosis and account for the later stage at diagnosis.[3,4][Level of evidence: I] These results are supported by a population-based case-control study suggesting a 1.7-fold (95% CI, 1.3-2.2) increased risk of breastcancer in women using combined hormone replacement therapy. The risk of invasive lobular carcinoma was increased 2.7-fold (95% CI, 1.7-4.3), the risk of invasive ductal carcinoma was increased 1.5-fold (95% CI, 1.1-2.0), and the risk of estrogen receptor-positive/progesterone receptor-positive breast cancer was increased 2.0-fold (95% CI, 1.5-2.7). Increased risk was highest for invasive lobular tumors and in women who used hormone replacement therapy for longer periods of time. Risk was not increased with unopposed estrogen therapy.