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Menopause Live - IMS Updates
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Date of release: 14 February, 2011

Breast cancer and postmenopausal hormone therapy


Another recent publication from the estrogen + progestin (E + P) arm of the Women’s Health Initiative (WHI) trial brings updated data on breast cancer [1]. The reason for the new paper lies in an extended, open follow-up period. The basic intervention time for the clinical trial was 5.6 years (standard deviation (SD) 1.3 years) (range 3.7–8.6 years), and the mean total follow-up period was 7.9 years (SD 1.4 years).In the E + P arm there were 385 cases of breast cancer (0.42% per year) vs. 293 cases in the placebo group (0.34% per year) (hazard ratio (HR) 1.25; 95% confidence interval (CI) 1.07–1.46; p = 0.004). Breast cancers in the E + P group were similar in histology and grade to breast cancers in the placebo group but were more likely to be node-positive (HR 1.78; 95% CI 1.23–2.58;p = 0.03). There were more deaths directly attributed to breast cancer (25 deaths (0.03% per year) vs. 12 deaths (0.01% per year); HR 1.96; 95% CI 1.00–4.04; p = 0.049) as well as more deaths from all causes occurring after a breast cancer diagnosis (51 deaths (0.05% per year) vs. 31 deaths (0.03% per year); HR 1.57; 95% CI 1.01–2.48; p = 0.045) among women who received E + P compared with women in the placebo group.

Comment

This recent publication from the WHI trial raises once again some uneasy feelings as to the need to continue to pump into the medical milieu and the media clinical information that has been already well chewed and heavily debated in regard to methodological issues and that is perhaps even biased. Basically, the association between long-term use of postmenopausal hormones and a slight increase in breast cancer risk is well documented and should be weighed carefully when the health-care provider discusses hormone therapy with his patient. However, the WHI investigators fail to put their results into the right perspective of absolute harm versus the significant expected benefits. They fail to stress the fact that hormone therapy today is prescribed in lower doses, and thus the doses used in the WHI trial are obsolete, especially in older women; they fail to mention that users of estrogen alone had in fact a reduced risk for breast cancer; they fail to stress the point that naïve users of hormones did not have an increased risk for breast cancer in the estrogen plus progestin arm, which makes the first period of use (up to 5 years, perhaps even more) quite safe in this respect; they fail to emphasize the absolute risk figures (in the current study, just two additional deaths per 10,000 women/year); they continue to use very elaborate, yet problematic statistical analyses, mixing data from the clinical trial with data derived from the observational study, or combining data from a randomized, placebo-controlled, double-blind protocol, with an open follow-up period when the WHI data were already known and had largely impacted on guidelines for hormone use and breast cancer surveillance. They also downgrade the implications of the age factor: the WHI study was designed to investigate an older cohort (mean age 63 years, with 70% of the participants above the age of 60 years). This certainly does not represent the typical population of younger, healthy women seeking hormone therapy because of bothersome vasomotor symptoms or other menopause-related complaints. It is noteworthy that another recent study pointed at a reduced risk for breast cancer in symptomatic postmenopausal women [2]. It seems that the WHI investigators are leading some political agenda against postmenopausal hormone therapy. When another publication from the WHI trial is released, the public and physicians believe that this is a new piece of information, while, in fact, most of it is actually a re-cycling of the same old material. Following the current publication, the media headlines stated ‘Hormones double the risk for breast cancer mortality’, which was statistically true, but in fact misleading. Being a billion-dollar, NIH-sponsored study should not guarantee automatic placing of any of the WHI results in the best medical journals unless proper consideration of their real scientific value and practical implications is seriously undertaken.

Comentario

Amos Pines
Department of Medicine T, Ichilov Hospital, Tel-Aviv, Israel

    References

  1. Chlebowski RT, Anderson GL, Gass M, et al. Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women. JAMA 2010;304:1684-92.
    http://www.ncbi.nlm.nih.gov/pubmed/20959578

  2. Huang Y, Malone KE, Cushing-Haugen KL, Daling JR, Li CI. Relationship between menopausal symptoms and risk of postmenopausal breast cancer. Cancer Epidemiol Biomarkers Prev 2011 Jan 18. Epub ahead of print.
    http://www.ncbi.nlm.nih.gov/pubmed/21212063