WHI: Reduced Risks–Benefits Associated With Estrogen or Estrogen Plus Progestin Therapy
The WHI reported a reduced risk of colon cancer in women on combination therapy; this equates to six women per 10,000 women. In the WHI study group that received estrogen only, estrogen replacement therapy did not effect the risk of colorectal cancer (Table 1). Other studies have found a slightly lower risk of colorectal cancer in women who have used estrogen replacement therapy for many years.
The WHI reported reductions of bone fractures (45 total fractures and five hip fractures per 10,000 women/year on combined HRT and six fewer hip and spine fractures and overall 56 fewer osteoporotic-related fractures in the estrogen alone arm), reduction in breast cancer (six less per 10,000/year) and reduced cardiovascular disease risk (five less per 10,000/year).[3,18,19] The overall number of deaths was reduced by six (49 in the estrogen only arm and 54 on placebo) (Table 1).[3,18,19]
The overall (reduced) risk for developing osteoporotic fracture in the combination therapy group, or (reduced) risk for osteoporotic fracture, breast cancer, and coronary heart disease (CHD) in women on estrogen alone in the WHI ranges between -0.45 and -0.67%.
Women's Health. 2011;7(4):475-485. © 2011 Future Medicine Ltd.
Cite this: Individualizing Hormone Therapy to Minimize Risk - Medscape - Jul 01, 2011.