Two decades of over-correction — what the trial actually showed, by age, by arm, and in absolute numbers.
For a symptomatic woman aged 50–60 within 10 years of her final period and without contraindications, benefits of MHT outweigh risks for most. Frame risk as natural frequencies: 'out of 1000 women like you taking combined therapy for 5 years, roughly 4 to 8 extra will be diagnosed with breast cancer.' Document that conversation. Never quote a relative risk alone.
Separate the arms and the progestogens. The breast cancer signal is largely progestogen-driven and appears smaller with micronised progesterone and dydrogesterone than with MPA in observational data (E3N, French cohorts) — though this has never been tested head-to-head in an RCT powered for breast cancer. Transdermal estradiol avoids first-pass hepatic effects and is not associated with increased VTE risk in observational and nested case-control data.
The methodological core of the WHI controversy: (1) the trial randomised to therapy, not to timing, so age-stratified analyses are subgroup analyses with the attendant multiplicity problems; (2) the CEE+MPA arm was stopped early on a global index driven substantially by the WHI's own monitoring boundary, inflating the effect estimate; (3) ELITE (Hodis 2016) provided the cleanest test of the timing hypothesis, showing slowed CIMT progression in the early-postmenopause stratum but not the late; (4) KEEPS and KEEPS-Continuation found no cognitive harm or benefit; (5) DOPS (Schierbeck 2012) was open-label and underpowered but directionally supportive.
“WHI proved that HRT causes breast cancer and heart attacks.”
WHI tested one oral regimen in women a mean of 12 years past menopause. The oestrogen-only arm showed fewer breast cancers. Coronary findings were driven by older initiators. The absolute excess risks in the combined arm are small and comparable to common lifestyle exposures, and all-cause mortality was unchanged over 18 years.
Systemic MHT is the most effective treatment for moderate-severe VMS
Established — RCT / guideline-grade — Consistent RCT evidence; 75–90% reduction in frequency.
CEE-alone in hysterectomised women did not increase breast cancer incidence in WHI
Established — RCT / guideline-grade — Non-significant reduction sustained in long-term follow-up.
Combined MHT increases breast cancer incidence with duration of use
Established — RCT / guideline-grade — Small absolute excess; risk attenuates after cessation.
Transdermal estradiol carries lower VTE risk than oral
Supported in defined populations — Large observational and nested case-control evidence; no dedicated RCT.
MHT started in women aged 50–59 reduces all-cause mortality
Promising but preliminary — Suggestive pooled and subgroup data; not a primary endpoint finding.
MHT should be prescribed to prevent dementia
Refuted or actively misleading — WHIMS showed increased dementia risk with late initiation; prevention is not an indication.
A 52-year-old with severe VMS and an intact uterus. Her maternal aunt had breast cancer at 68. She has read that 'HRT causes cancer' and is frightened but exhausted.
Which approach best supports an informed decision?
A 64-year-old, 13 years postmenopause, requests MHT for ongoing night sweats. BMI 31, treated hypertension, non-smoker.
Most appropriate management?
In WHI, the oestrogen-alone (CEE) arm showed which effect on breast cancer incidence?
The best way to communicate MHT breast cancer risk in consultation is:
ELITE (Hodis 2016) tested which hypothesis?
Over 18 years of cumulative WHI follow-up, all-cause mortality in MHT users was: