Dec. 2, 2004
Statement by Sidney M. Wolfe, MD
Director, Public Citizen’s Health Research Group
Before the FDA Reproductive Health Advisory Committee
Concerning the Transdermal Testosterone Patch
Is an increase in approximately one sexually satisfying encounter a month (not from zero to one, but from approximately four to five times per month) worth the possibility of an increase in breast cancer or coronary artery disease? Is the U.S. Food and Drug Administration (FDA) – technically an agency of the Public Health Service – actually considering the approval of this product?
In the words of the FDA medical officer who reviewed this product, “The crucial question is the clinical significance of the change with active treatment yielding, on average, one more satisfying sexual event per four weeks compared to placebo.” There was similar skepticism by the FDA reviewer of the improvement in sexual desire attributable to the testosterone patch. The comment was, “The clinical significance of the increase with active treatment yielding, on average, an increase of only 5-6 points more than placebo on a scale of 100 [for sexual desire] is unknown.”
There is a fairly good consensus among epidemiologists working in the area of endogenous (body-produced) hormones and breast cancer risk that increasing levels of the common estrogens and androgens (such as testosterone) are strongly associated with increasing levels of breast cancer risk. This is best illustrated by the pooled analysis of nine high-quality prospective studies that have addressed this issue, published by “The Endogenous Hormones and Breast Cancer Collaborative Group” (Journal Natl Cancer Inst 2002; 94: 606-16). In this pooled analysis, the risk of breast cancer for postmenopausal women increased by approximately two-fold with a quadrupling of blood testosterone levels.
In the data on the transdermal testosterone patch, discussed on page 58 of the FDA review, the average blood level of testosterone in reproductive age (18-49) women using the patch rose from a pre-treatment baseline level of 176 nanograms per liter to 797 nanograms per liter by week 52 while using the patch. This represents an average 4.5-fold increase in blood testosterone levels by 52 weeks. This increase is actually slightly larger than the four-fold increase in blood testosterone levels in the pooled study mentioned above that was associated with a two-fold increased risk of breast cancer.
Other concerns about the chronic use of testosterone patches include increased risk of coronary artery disease. A study entitled “Relationship between serum sex hormones and coronary artery disease in postmenopausal women” found “evidence of a positive relationship between the serum free testosterone level and the degree of coronary artery disease in women.” (Free testosterone levels increased by more than four-fold with the transdermal testosterone patch.) We also agree with FDA reviewers who stated that “Intrinsa is a product that will potentially be used on a chronic, long-term basis, and thus, might induce women to continue use of estrogen well beyond the duration [lowest effective doses and for the shortest duration] that would be recommended for management of menopausal symptoms.”
Decreased sexual desire is a very complicated problem, as discussed by Dr. Tiefer today. There is little question that a large proportion of women with this complaint respond very well to counseling that may reveal underlying problems such as a history of being sexually abused, current unstable or unhealthy relationships, depression or other causes better dealt with directly rather than being glossed over with a testosterone patch. The journalist H.L. Mencken has said that for every complicated problem there is a simple solution – which is usually wrong. I urge you and the FDA to reject the application for approval of the testosterone patch.