A meta-analysis was performed to explore the association between MHT use and breast cancer survival «Yu X, Zhou S, Wang J, ym. Hormone replacement ther...»1. The review included forty cohort studies and two case–control studies involving 1,756,833 women. In all, 32 studies reported on the association between prediagnosis MHT and breast cancer survival and ten studies reported on the association between postdiagnosis MHT and beast cancer survival. Prediagnosis MHT was defined as having received MHT at the time of diagnosis or at any time before diagnosis. The prediagnosis MHT use was associated with decreased risk of dying from breast cancer (HR = 0.88, 95% CI 0.81–0.97) or any cause (HR = 0.79, 95% CI 0.69–0.90).
In the subgroup analyses, patients who were current users at diagnosis or who received combined hormone therapy before diagnosis seemed to show more benefit from MHT use. In conclusion, the average effect of MHT use seems not to compromise breast cancer survival.
Comment: Age of the study populations as well as MHT regimen was not reported. The level of evidence is downgraded due to the observational study design of the original trials.