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Tenth Anniversary of Initial Women’s Health Initiative (WHI) Report . Richard Santen, MD University of Virginia 12/2/ 11. Tenth Anniversary of Initial Women’s Health Initiative (WHI) Report . What have we learned? How should the public be informed?
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Tenth Anniversary of Initial Women’s Health Initiative (WHI) Report Richard Santen, MD University of Virginia 12/2/11
Tenth Anniversary of Initial Women’s Health Initiative (WHI) Report • What have we learned? • How should the public be informed? • What should a post-menopausal woman do, based on what we now know?
WHI • First report 2002 • Two arms • Placebo versus conjugated equine estrogen plus MPA (E+P) • Placebo versus conjugated equine estrogen alone (E) • 80% reduction in menopausal hormone use over the next five years
WHI 10 years later:key conclusions after a decade of reflection • Need to consider all information based on excess risk and benefit and not relative risk and benefit • Only women just entering menopause are candidates for menopausal hormone therapy
Initial WHI Report 2002major finding 26% increase in risk of breast cancer
My wife immediately asked me Do I have a 26% chance of getting breast cancer since I have taken hormones for more than 5 years? That is a one in four chance. Is this really true?
My answer No, the 26% increase represents only relative risk. Her reply What does that mean for me?
Important Issue • We need to distinguish between: • relative risk • absolute risk • excess risk
This is how I explain this to my wife
120,000 of these women or 12% will develop breast cancer in their lifetimes This is absolute risk
12,000 or 1% willdevelop breast cancer in five years Absolute risk
How many of these women will get breast cancer within five years?
18 Women not receiving MHT will develop breast cancer over a five year period Absolute risk
26% increase in relative risk in WHI
If these 1000 women take MHT for five years, 22 women will develop breast cancer
However, only 4 of these 1000 women would develop a breast cancer that they would not otherwise have developed. Technically this is called attributable risk. 18 with breast cancer without MHT 22 with breast cancer with MHT Excess risk 4
My Answer: Based on the WHI study, you will only have a 4 in 1000 chance of getting a breast cancer that you would not otherwise have gotten if you take MHT for 5 years
WHI 10 years later • Relative risk is only important when absolute risk is high • Example from common experience
Example of relative vs absolute risk • If you take one plane flight your chances of crashing are one in ten million (absolute risk) • Your relative risk of crashing is increased by 500% if you take five plane flights . • Your excess risk by taking five flights rather than one is four per ten million • Bottom line: relative risk means little when absolute risk is low • This is the reason to convert all WHI data to excess risk or benefit
WHI 10 years later • Need to consider all risk and benefit data consistently • The Endocrine Society has expressed all risks and benefits as the number of women per 1000 using MHT for 5 years who will experience event
What are the major excess risks reported in the original WHI study?
WHI E+P Average age 63 Benefits Risks
Timing HypothesisEarly vs. late treatment Late Early
Timing HypothesisEarly vs. late treatment Early Late
VTE and Stroke Similar relative increase in risk but younger women experience these problems less commonly
MHT 10 years after WHIonly used at start of menopause Risks Benefits
For Some in Menopause, Hormones May Be Only Option By TARA PARKER-POPE New York Times August 15, 2011
MHT 10 years after WHIwomen with severe symptoms Risks Benefits
Low risk of breast cancer High risk of breast cancer Benefit Risk
Assess risk of breast cancer and only treat those at low risk • Low risk (i.e. 0.5% chance of breast cancer in 5 year) excess risk is 2.5/1000 per 5 years • High risk (i.e. 4% chance of breast cancer in 5 years) excess risk 20/1000/5 years
BMI MHT Plasma E2 Breast Density Age at Menarche Age at Menopause Age at 1st Live birth Breast Cancer Risk Factors by Group RR Estrogen Related Risk Factors 6 5 4 3 2 1 0
Alcohol 1oRelative 2o Relative Breast Cancer Risk Factors by Group RR Other Risk Factors Estrogen Related Risk Factors 6 5 4 3 2 1 0 BMI MHT Plasma E2 Breast Density Age at Menarche Age at 1st Live birth Age at Menopause
Calculation of Breast Cancer Risk • Gail Model (http://www.cancer.gov/bcrisktoolmobile) • Tyrer-CuzickModel (http://pulsescreening.co.uk/Corporate/Breast_cancer_prediction_model-1.pdf)
For Some in Menopause, Hormones May Be Only Option By TARA PARKER-POPE New York Times August 15, 2011
WHI after 10 years The Ultimate Goal is to provide the most benefit to the patient while avoiding the most risks