Long-Term Treatment of Transsexuals with Cross-Sex Hormones: Extensive Personal Experience
Louis J. Gooren, Erik J. Giltay, and Mathijs C. Bunck
Department of Endocrinology (L.J.G., M.C.B.), Vrije Universiteit University Medical Center, 1081 HV Amsterdam, The Netherlands; andLeiden University Medical Center (E.J.G.), Department of Psychiatry, 2333 ZA Leiden, The Netherlands
Context: Transsexuals receive cross-sex hormone treatment. Its short-term use appears reasonably safe. Little is known about its long-term use. This report offers some perspectives. Setting: The setting was a university hospital serving as the national referral center for The Neth- erlands (16 million people). Patients: From the start of the gender clinic in 1975 up to 2006, 2236 male-to-female and 876 female-to-male transsexuals have received cross-sex hormone treatment. In principle, subjects are followed up lifelong. Interventions: Male-to-female transsexuals receive treatment with the antiandrogen cyproterone acetate 100 mg/d plus estrogens (previously 100 g ethinyl estradiol, now 2– 4 mg oral estradiol valerate/d or 100 g transdermal estradiol/d). Female-to-male transsexuals receive parenteral tes- tosterone esters 250 mg/2 wk. After 18 –36 months, surgical sex reassignment including gonadec- tomy follows, inducing a profound hypogonadal state. Main Outcome Measures: Outcome measures included morbidity and mortality data and data assessing risks of osteoporosis and cardiovascular disease. Results: Mortality was not higher than in a comparison group. Regarding morbidity, with ethinyl estradiol, there was a 6 – 8% incidence of venous thrombosis, which is no longer the case with use of other types of estrogens. Continuous use of cross-sex hormones is required to prevent osteo- porosis. Androgen deprivation plus an estrogen milieu in male-to-female transsexuals has a larger deleterious effect on cardiovascular risk factors than inducing an androgenic milieu in female-to- male transsexuals, but there is so far no elevated cardiovascular morbidity/mortality. Low numbers of endocrine-related cancers have been observed in male-to-female transsexuals. Conclusions: Cross-sex hormone treatment of transsexuals seems acceptably safe over the short and medium term, but solid clinical data are lacking. (J Clin Endocrinol Metab 93: 19 –25, 2008) Transsexualism is the condition in which a person with ap- hormone treatment will not be addressed here, but guidelines
parently normal somatic sexual differentiation is con-
provided by the World Professional Association for Transgender
vinced that she or he is actually a member of the other sex. This
Health (http://www.wpath.org) were followed.
conviction is accompanied by an irresistible urge to live in the
The acquisition of the secondary sex characteristics of the
other gender, which requires hormonal, anatomical, legal, and
other gender is fundamental to sex reassignment. Acquisition of
psychosocial adaptations. Since its initiation in 1975, 876 fe-
these secondary sex characteristics is contingent on sex steroids.
male-to-male (F2M) and 2236 male-to-female transsexuals
There is no known essential difference in sensitivity to the bio-
(M2F) have received hormonal treatment. Eligibility criteria for
logical action of sex steroids on the basis of genetic configura-
Abbreviations: F2M, Female-to-male; HDL, high-density lipoprotein; LDL, low-density li-
Copyright 2008 by The Endocrine Society
doi: 10.1210/jc.2007-1809 Received August 13, 2007. Accepted October 29, 2007.
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
tions or gonadal status. The typical transsexual requesting treat-
progestational drugs can be stopped. When F2M receive treat-
ment is a young to middle-aged and healthy person, and
ment with testosterone, part of it is aromatized to estradiol (5).
therefore, there are usually no or few absolute or relative con-
When hysterectomy is delayed, there is some concern about en-
traindications against cross-sex hormone administration. For
suppression of androgen secretion or action, several agents areavailable. In Europe, the most widely used drug is cyproteroneacetate (usually 50 mg twice daily), a progestational compound
Long-Term Treatment and Its Effect on Health
with antiandrogenic properties. If not available, medroxypro-gesterone acetate, 5–10 mg/d, is a less effective alternative. Spi-
After reassignment surgery, which includes gonadectomy, hor-
ronolactone (up to100 mg twice daily, if tolerated), a diuretic
mone therapy must be continued. It is reasonable to assume that
with antiandrogenic properties, has similar effects. Long-acting
the principles of treatment are very similar to those of other
GnRH inhibit gonadotropin secretion. Finasteride (5 mg/d), a
subjects without their own gonadal hormonal secretion. An un-
5␣-reductase inhibitor, might also be considered. Hormone
resolved question is whether in the long term all functions of sex
treatment of transsexuals has been reviewed in recent years (1, 2).
steroids of a subject are adequately covered by cross-sex hor-mones and whether the administration of cross-sex hormones isappropriately safe, or at least as safe as administration of sex
M2F Transsexual Treatment
steroids in a subject receiving long-term sex-appropriate sex ste-roids. There are presently no indications that there are funda-
There is a wide range of estrogens from which to choose. Oral
mental sex differences in sensitivity to hormone action of sex
ethinyl estradiol (50 –100 g/d) is a potent and inexpensive es-
steroids. Nearly all hormone-related biochemical processes can
trogen but may cause venous thrombosis, particularly in those
be sex reversed by the administration of cross-sex hormones.
over age 40 (1, 3). It should therefore not be used in the dosage
It is likely that that there is an underreporting of (serious)
required by M2F (50 –100 g/d). Oral 17-estradiol valerate,
complications of cross-sex hormone therapy. Although the ini-
2– 4 mg/d, or transdermal 17-estradiol, 100 g twice a week,
tial treatment with cross-sex hormones is mainly concentrated in
are the treatments of choice and are much less thrombogenic than
specialized centers, complications occurring in the long term are
ethinyl estradiol (3). Many transsexuals favor injectable estro-
seen in general practice, and these complications are only occa-
gens, because they generate high levels of circulating estrogens.
sionally reported in the scientific literature. The authors have
However, they have the potential risk of overdose.
been contacted by other physicians on medical occurrences in
There is no evidence that progestagens add to the feminiza-
transsexuals, but these cases are often lost for follow-up and for
tion process of M2F. In female reproductive endocrinology, pro-
registration of (potential) complications of cross-sex hormonal
gesterone prepares the uterus for conception and the breasts for
treatment. The latter situation prevents a fair comparison with
lactation. Some patients strongly believe that progestagens are a
epidemiological data in the general population. Recently, a web
necessary addition to estrogens in their feminization process. But
site has been opened for reporting side effects of cross-sex hor-
this is not the case, and progestagens may have side effects, such
mone treatment: http://www.wpath.org/resources_transgender.
as salt/water retention leading to elevated blood pressure or ve-
cfm (click under transgender information: resource links).
nous varicosis. In the large-scale study of postmenopausal hor-
In 1997, we published a report on mortality/morbidity in
mone use in women, the combination of estrogens and proge-
transsexual subjects (7). This was a retrospective, descriptive
stagens appeared to be associated with a higher incidence of
study of 816 M2F and 293 F2M who had been treated with
breast cancer (4) and cardiovascular disease.
cross-sex hormones for a total of 10,152 patient-years. Stan-dardized mortality and incidence ratios were calculated from thegeneral Dutch population (age- and gender-adjusted) and they
F2M Transsexual Treatment
were also compared with side effects of cross-sex hormones intranssexuals reported in the literature. Mortality was not higher
The goal of treatment in the F2M is to induce virilization (in-
than in the general population. Venous thrombosis occurred fre-
cluding a deepening of the voice), production of male-pattern
quently but could be related to the use of oral ethinyl estradiol
body hair growth and physical contours, and cessation of men-
(3), and the incidence decreased to the incidence in the general
ses. The principal hormonal treatment used to accomplish these
population when its use was relinquished. The conclusion of the
goals is a testosterone preparation. The most commonly used
report was that in the short and midterm, cross-sex hormone
preparations are injectable testosterone esters administered im in
doses of 200 –250 mg every 2 wk. In some countries, testosterone
Cross-sex hormone administration took off in the 1970s, so
undecanoate (1000 mg) is available, and injections may be
several transsexual subjects are now in their 60s, 70s, and even
spaced at 10 –12 wk. Use of androgen gel or transdermal patches
80s. Another important but unresolved question is until what age
can also provide good, steady-state testosterone levels. Occa-
cross-sex hormone treatment must be continued. This question
sionally, menstrual bleeding does not cease, and the addition of
must be set against the information that has become available on
a progestational agent is necessary, almost always needed when
hormone replacement therapy in perimenopausal and post-
transdermal or oral testosterone is used.
menopausal women (National Institutes of Health State-of-the-
After ovariectomy, androgen therapy must be continued, but
Science Conference Statement on management of menopause-
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
related symptoms). Should estrogen administration to M2F be
mone administration to transsexuals on (biochemical) risk fac-
discontinued for the reasons applicable to postmenopausal
women? Not needing progestagens to prevent estrogen stimu-lation of uterine hyperplasia and malignancy, would M2F ben-
Cardiovascular risk in M2F transsexuals
efit from continued estrogen-only administration in view of the
Men with prostate cancer, treated with androgen depriva-
reportedly favorable effects of estrogens on bone, the cardiovas-
tion, develop an increase of fat mass with an altered lipid profile
cular system, and the brain? The issue seems less pressing in F2M
(13). These patients also appear to develop insulin resistance,
receiving treatment with testosterone because in this group there
hyperinsulinemia, and hyperglycemia (13). The risks of diabetes
is no high risk of androgen-related malignancies. Transsexuals
mellitus increase by 44% and mortality of cardiovascular dis-
themselves are usually inclined to continue cross-sex hormone
eases by 16% during a follow-up of up to 10 yr. Is there a parallel
administration for fear that they would lose physical character-
Several studies have been done in M2F transsexuals who re-
The following will address some areas where sex hormones
ceived estrogens and antiandrogens (either 100 g ethinyl estra-
are known to play a role and continuation/discontinuation and
diol per day or transdermal 17-estradiol 100 g twice a week,
dose of hormone administration may be relevant.
with or without 100 mg cyproterone acetate). Many changes incardiovascular risk factors were found, and the results of thesestudies in M2F are summarized in Table 1. Cross-Sex Hormones and Osteoporosis
Weight, body mass index, total body fat, and visceral fat
increased during treatment in M2F (Table 1), resembling fea-
Sex steroids play a pivotal role in the maintenance of the integrity
tures of the metabolic syndrome. The observed changes in car-
of the skeleton in both men and women. Postmenopausal women
diovascular risk factors observed in transsexual patients may be
and hypogonadal men have an increased risk of fractures. The
primarily caused by the increase of the amount of visceral fat in
risk of bone loss in subjects undergoing sex reassignment has
M2F (14, 15). The increase in fat tissue may lead to an increased
been well recognized in the literature (8 –11). In the longer term,
hepatic triglyceride influx and a rise of plasma leptin (14).
bone mineral density is preserved during cross-sex hormone ad-
High-density lipoprotein (HDL) cholesterol, its subfractions,
ministration (10). Apparently, estrogens alone are capable of
and triglyceride levels increased (Table 1), to a similar extent as
maintaining bone mass in M2F. Conversely, testosterone ad-
seen in men treated for prostate cancer (13). Total cholesterol
ministration maintains bone mineral density in F2M. Part of
was unaffected, and low-density lipoprotein (LDL) cholesterol
testosterone is converted to estradiol, resulting in circulating es-
levels decreased by 12% in M2F (14), whereas total and LDL
tradiol levels well above the plasma level of estradiol critical for
cholesterol levels were found to increase by 9% in men treated
preserving bone mineral density in men (i.e. 40 –50 pmol/liter)
for prostate cancer (13). The low estrogen state observed in these
(5). In our study, there was an inverse relationship between se-
men is responsible for the increases in total and LDL cholesterol.
rum LH concentrations and bone mineral density, so serum LH
The latter was not observed in our transsexual patients who
may serve as an indicator of the adequacy of sex steroid admin-
receive, in addition to the androgen deprivation, treatment with
istration (10). It is not known whether cross-sex hormone ad-
estrogens. The slight decrease in LDL cholesterol seen in trans-
ministration can be responsibly discontinued at a certain age
sexuals was, however, accompanied by a decrease in LDL par-
without inducing an unacceptable risk of osteoporosis and bone
ticle size (14), another known cardiovascular risk factor. A study
by another group found that administering GnRH agonists plusoral 17-estradiol valerate to M2F induced endocrine changessimilar to our studies but without an impairment of the lipid
Cross-Sex Hormones and Cardiovascular
profile. The use of cyproterone acetate might explain the differ-
ences. Indeed, a study using cyproterone acetate in prostate can-cer patients found a serious deterioration of the lipid profile.
Men have a higher incidence of cardiovascular events than
The effects on insulin sensitivity encountered in our studies
women of similar ages (12). There is, however, no evidence sup-
were largely in the same detrimental direction (14) as in men with
porting a causal relation between higher testosterone levels and
prostate cancer treated with GnRH agonists (13). The deleteri-
heart disease (12). There is as yet no true insight into the effects
ous effects on insulin sensitivity are, therefore, likely due to an-
of cross-sex hormone treatment on cardiovascular health. As can
drogen deprivation. We found that insulin sensitivity (assessed
be expected, cases of cardiovascular complications of transsex-
by hyperinsulinemic euglycemic clamp) decreased, and this was
uals have been reported in the literature, but it is not warranted
accompanied by a compensatory increase in fasting plasma in-
to generalize them to the whole population of transsexuals.
sulin concentration preventing hyperglycemia (Table 1) (14). En-
There is as yet no true insight into the effects of cross-sex hor-
dogenous glucose production (measured by isotope dilution with
mone treatment on cardiovascular health. As can be expected,
titrated glucose) was, however, not affected by cross-sex hor-
cases of cardiovascular complications of transsexuals have been
mone administration, indicating that the observed changes in
reported in the literature, but it is not warranted to generalize
glucose requirement during a hyperinsulinemic euglycemic
them to the whole population of transsexuals. Over the past 15
clamp procedure were due to the diminished peripheral glucose
yr, we have extensively investigated the effects of cross-sex hor-
uptake (16), a finding that was later confirmed by Elbers et al.
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
TABLE 1. Changes over 4 –12 months in risk factors for cardiovascular disease in M2F transsexuals Effect on CVD morbidity/ Absolute change Relative change mortality
Tissue-type plasminogen activator antigen
Plasminogen activator inhibitor-1 antigen
Ϫ, No change in CVD risk; 1, increased CVD risk; 2, decreased CVD risk; CVD, cardiovascular disease; DHA, docosahexaenoic acid; LBM, lean body mass; MRI,magnetic resonance imaging; NS, no statistically significant change.
(14). We further found that blood pressure slightly increased
HDL cholesterol, fasting triglycerides, total homocysteine, and
during estrogen and antiandrogen treatment, and there was a
C-reactive protein (Table 2). Blood pressure and arterial stiff-
small detrimental effect on arterial stiffness (17).
ness, unlike in other reports, were unaffected by cross-sex hor-mone treatment (17). Cardiovascular risk in F2M transsexuals
Hyperandrogenism in women, usually resulting from the
polycystic ovarian syndrome, is associated with an unfavorable
Concluding remarks on cardiovascular risk
cardiovascular risk profile. However, hyperandrogenism in
Cross-sex hormone administration in M2F and F2M both
polycystic ovarian syndrome is usually clustered with features of
improves and impairs profiles of cardiovascular risk factors. It
the metabolic syndrome (hyperinsulinemia, visceral obesity, hy-
remains difficult to determine how much weight must be attrib-
pertension, and dyslipidemia). It is difficult to disentangle the
uted to these alterations in risk factors and whether these changes
contributions that the various components of the metabolic syn-
are of clinical significance. With these reservations in mind, the
drome make to this unfavorable cardiovascular risk profile,
overall impression is that inducing androgen deprivation and an
more precisely, what the role of hyperandrogenism per se is.
estrogen milieu in M2F has a larger deleterious effect on the risk
The results from studies in F2M transsexuals are summarized
factors, than inducing an androgenic milieu in F2M (Tables 1
in Table 2. The observed changes in cardiovascular risk factors
seen in F2M may again be secondary to the increase in weight and
So far the only data available on hard clinical endpoints is
the amount of visceral fat (14). Our group has shown that tes-
from our study on cardiovascular morbidity and mortality in
tosterone administration to F2M decreases plasma leptin (14);
both M2F and F2M (7). This study reports no elevated (cardio-
furthermore, a decrease in serum adiponectin concentration has
vascular) morbidity and/or mortality in the cohort of transsex-
been reported. We found a slight decrease of insulin sensitivity in
uals treated at the Amsterdam clinic. Yet, to reduce the risk of the
one of our studies (14, 16). Furthermore, increases were found in
metabolic syndrome and cardiovascular disease and to increase
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
TABLE 2. Changes over 4 –12 months in risk factors for cardiovascular disease in F2M transsexuals Effect on CVD morbidity/ Absolute change Relative change mortality
Tissue-type plasminogen activator antigen
Plasminogen activator inhibitor-1 antigen
Ϫ, No change in CVD risk; 1, increased CVD risk; 2, decreased CVD risk; CVD, cardiovascular disease; DHA, docosahexaenoic acid; LBM, lean body mass; MRI,magnetic resonance imaging; NS, no statistically significant change.
life expectancy, it is important to advise transsexuals to adopt
following is a summary of reports in the literature on tumors in
healthy lifestyle and dietary behaviors.
The first documented hormone treatments of transsexuals
started in the 1970s, and the length of time of exposure to hor-mones may have been too short for tumors to manifest them-
Cross-Sex Hormones and Hormone-Dependent
selves. Therefore, the conclusion that hormone-related tumors
are not highly prevalent among the transsexual population must
Some cancers (of reproductive organs) are hormone related.
Hormone-dependent tumors are practically not occurring inhormonally treated F2M and seem a rare occurrence in M2F. But
Lactotroph adenoma
transsexualism is a rare phenomenon (the highest estimates are
Several cases of lactotroph adenoma (prolactinoma) after
one in 12,000 males and one in 30,000 females) (18); if, in ad-
high-dose estrogen administration have been reported in patients
dition, the prevalence of hormone-dependent tumors is low, this
with normal serum prolactin concentrations before therapy (7,
may lead to an underestimation of tumors.
19 –21). We have recently encountered a case of development of
M2F, as a rule, use higher doses of estrogens than women
a pituitary microprolactinoma in a M2F, only occurring after 14
lacking production of gonadal hormones. In transsexuals, ex-
yr of normal-dose estrogen treatment. Although causality has
posure to estrogens is usually over a shorter period of lifetime,
not been established, we recommend that serum prolactin levels
because transsexuals mostly start cross-sex hormone treatment
continue to be monitored in estrogen-treated M2F in the long
well after puberty, although this is changing. Presently, adoles-
cent transsexuals may be eligible for cross-sex hormone treat-ment. Furthermore, transsexuals beyond the ages of 50 or 60 yr
Breast cancer
have a strong inclination to continue cross-sex hormones, in-
There are two reports of M2F who developed breast carci-
creasing their period of time of exposure to sex steroids. The
nomas while receiving estrogen treatment (22, 23). Breast fibro-
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
adenomas in M2F receiving hormonal treatment have been ob-
tenable, but there is an up-regulation of androgen receptors in
served. In our series of approximately 2200 M2F, cumulative
ovarian and uterine tissue in long-term treated F2M (32).
over 30 yr, until recently, no single case of breast cancer had beenobserved, but there is now one case. On the basis of the aboveinformation, one would be inclined to think that breast carci-
Conclusions
nomas in M2F are rare, but it has to be kept in mind that 1800subjects, with a strong variation in estrogen exposure (from 1–25
It is now clear that sex reassignment of transsexuals benefits their
yr), do not allow firm conclusions in assessing risk. Aging is a
well-being, (33) although suicide rates remain high (7). Regrets
factor in the development of cancer, and prolonged exposure to
are rare (0.5–3.0%). Cross-sex hormone administration to
estrogens may also prove to be a factor. Therefore, the discussion
transsexuals is acceptably safe in the short and medium term.
as to the age at which estrogen treatment in M2F should be
However, potentially adverse effects in the longer term are pres-
terminated is pertinent. In any case, in addition to regular med-
ently unknown. The data, although limited, of surrogate markers
ical examination, breast self-examination must be part of the
of cardiovascular disease and the reports of cancer in transsex-
monitoring of estrogen administration, following the same
uals leave room for a cautious optimism. But true insight can only
guidelines that exist for other women.
come from close monitoring and thorough reporting of adverse
Amazingly, breast cancer has been reported in a F2M after
bilateral sc mastectomy while receiving treatment with testos-terone. This occurred in residual mammary tissue after 10 yr oftreatment with testosterone, which is partially aromatized to
Acknowledgments
We thank Professor David Handelsman, ANZAC Research Institute,Sydney, Australia, for his helpful comments. Benign prostate hyperplasia and prostate cancer
Address all correspondence and requests for reprints to: Dr. L. J.
The prostate is not removed with sex reassignment surgery.
Gooren, Department of Endocrinology, VU University Medical Center,
Prostatectomy is a surgically cumbersome operation, with pos-
De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands. E-mail:
sible complications, such as urinary incontinence. As expected,
Disclosure Statement: The authors have nothing to declare.
the prostate volume shrinks after androgen deprivation. Estro-gen exposure does not induce signs of hyperplasia or (pre)ma-lignancy (25). Two cases of benign prostate hyperplasia, requir-ing transurethral prostate resection, have been described in
References
subjects who had been orchidectomized and had been treated
1. Gooren L 2005 Hormone treatment of the adult transsexual patient. Horm Res
with only estrogens for more than 20 yr. Another case of squa-
mous metaplasia of the verumontanum has been reported, lead-
2. Moore E, Wisniewski A, Dobs A 2003 Endocrine treatment of transsexual
people: a review of treatment regimens, outcomes, and adverse effects. J Clin
ing to obstruction due to hypertrophy (26).
Three cases of prostate cancer in M2F taking estrogen have
3. Toorians AW, Thomassen MC, Zweegman S, Magdeleyns EJ, Tans G, Gooren
been reported (27–29). It is not clear whether these cancers were
LJ, Rosing J 2003 Venous thrombosis and changes of hemostatic variables during cross-sex hormone treatment in transsexual people. J Clin Endocrinol
estrogen sensitive or whether they were present before beginning
estrogen administration and then subsequently dedifferentiated
4. Chlebowski RT, Hendrix SL, Langer RD, Stefanick ML, Gass M, Lane D,
to become androgen independent. These patients were each over
Rodabough RJ, Gilligan MA, Cyr MG, Thomson CA, Khandekar J, Petrovitch H, McTiernan A 2003 Influence of estrogen plus progestin on breast cancer
50 yr of age when they started cross-sex hormone treatment
and mammography in healthy postmenopausal women: the Women’s Health
(with total androgen ablation). Epidemiological studies have
Initiative Randomized Trial. JAMA 289:3243–3253
shown that orchidectomy before age 40 prevents the develop-
5. Spinder T, Spijkstra JJ, van den Tweel JG, Burger CW, van Kessel H, Hompes PG, Gooren LJ 1989 The effects of long term testosterone administration on
ment of prostate cancer and benign prostate hyperplasia, and the
pulsatile luteinizing hormone secretion and on ovarian histology in eugonadal
above cases do not contradict this notion. In most clinics, screen-
female to male transsexual subjects. J Clin Endocrinol Metab 69:151–157
ing for the development of levels of prostate-specific antigen is
6. Futterweit W, Deligdisch L 1986 Histopathological effects of exogenously
administered testosterone in 19 female to male transsexuals. J Clin Endocrinol
7. van Kesteren PJ, Asscheman H, Megens JA, Gooren LJ 1997 Mortality and
morbidity in transsexual subjects treated with cross-sex hormones. Clin En-
Ovarian cancer
Ovariectomy is recommended in F2M when they are eligible
8. Lips P, Asscheman H, Uitewaal P, Netelenbos JC, Gooren L 1989 The effect
of cross-gender hormonal treatment on bone metabolism in male-to-female
for surgical sex reassignment, in our clinic, usually 18 –24
transsexuals. J Bone Miner Res 4:657– 662
months after the start of testosterone administration. We have
9. Lips P, van Kesteren PJ, Asscheman H, Gooren LJ 1996 The effect of androgen
observed two cases of ovarian carcinoma in testosterone-treated
treatment on bone metabolism in female-to-male transsexuals. J Bone MinerRes 11:1769 –1773
F2M, diagnosed before they underwent surgery (30). Another
10. Van Kesteren P, Lips P, Gooren LJ, Asscheman H, Megens J 1998 Long-term
case has been reported recently (31).
follow-up of bone mineral density and bone metabolism in transsexuals treated
The ovaries of F2M transsexuals taking androgens resemble
with cross-sex hormones. Clin Endocrinol (Oxf) 48:347–354
11. Reutrakul S, Ongphiphadhanakul B, Piaseu N, Krittiyawong S, Chanpraser-
polycystic ovaries (5). The earlier notion that polycystic degen-
tyothin S, Bunnag P, Rajatanavin R 1998 The effects of oestrogen exposure on
erated ovaries are more prone to develop cancer appears not
bone mass in male to female transsexuals. Clin Endocrinol (Oxf) 49:811– 814
J Clin Endocrinol Metab, January 2008, 93(1):19 –25
12. Liu PY, Death AK, Handelsman DJ 2003 Androgens and cardiovascular dis-
Metastatic prostatic carcinoma in a male-to-female transsexual. Br J Urol
13. Smith RM LH, Nathan DM 2006 Insulin sensitivity during combined andro-
28. Dorff TB, Shazer RL, Nepomuceno EM, Tucker SJ 2007 Successful treatment
gen blockade for prostate cancer. J Clin Endocrinol Metab 91:1305–1308
of metastatic androgen-independent prostate carcinoma in a transsexual pa-
14. Elbers JM, Giltay EJ, Teerlink T, Scheffer PG, Asscheman H, Seidell JC,
tient. Clin Genitourin Cancer 5:344 –346
Gooren LJ 2003 Effects of sex steroids on components of the insulin resistance
29. Thurston AV 1994 Carcinoma of the prostate in a transsexual. Br J Urol
syndrome in transsexual subjects. Clin Endocrinol (Oxf) 58:562–571
15. Elbers JM, Asscheman H, Seidell JC, Gooren LJ 1999 Effects of sex steroid
30. Hage JJ, Dekker JJ, Karim RB, Verheijen RH, Bloemena E 2000 Ovarian
hormones on regional fat depots as assessed by magnetic resonance imaging in
cancer in female-to-male transsexuals: report of two cases. Gynecol Oncol
transsexuals. Am J Physiol 276:E317–E325
16. Polderman KH, Gooren LJ, Asscheman H, Bakker A, Heine RJ 1994 Induction
31. Dizon DS, Tejada-Berges T, Koelliker S, Steinhoff M, Granai CO 2006 Ovar-
of insulin resistance by androgens and estrogens. J Clin Endocrinol Metab
ian cancer associated with testosterone supplementation in a female-to-male
transsexual patient. Gynecol Obstet Invest 62:226 –228
17. Giltay EJ, Lambert J, Gooren LJ, Elbers JM, Steyn M, Stehouwer CD 1999 Sex
32. Chadha S, Pache TD, Huikeshoven JM, Brinkmann AO, van der Kwast TH
steroids, insulin, and arterial stiffness in women and men. Hypertension 34:
1994 Androgen receptor expression in human ovarian and uterine tissue of
long-term androgen-treated transsexual women. Hum Pathol 25:1198 –1204
33. Smith YL, Van Goozen SH, Kuiper AJ, Cohen-Kettenis PT 2005 Sex reassign-
18. Van Kesteren PJ, Gooren LJ, Megens JA 1996 An epidemiological and demo-
ment: outcomes and predictors of treatment for adolescent and adult trans-
graphic study of transsexuals in The Netherlands. Arch Sex Behav 25:589 –
34. Giltay EJ, Verhoef P, Gooren LJ, Geleijnse JM, Schouten EG, Stehouwer CD
19. Gooren LJ, Assies J, Asscheman H, de Slegte R, van Kessel H 1988 Estrogen-
2003 Oral and transdermal estrogens both lower plasma total homocysteine
induced prolactinoma in a man. J Clin Endocrinol Metab 66:444 – 446
in male-to-female transsexuals. Atherosclerosis 168:139 –146
20. Kovacs K, Stefaneanu L, Ezzat S, Smyth HS 1994 Prolactin-producing pituitary
35. Giltay EJ, Hoogeveen EK, Elbers JM, Gooren LJ, Asscheman H, Stehouwer CD
adenoma in a male-to-female transsexual patient with protracted estrogen
1998 Effects of sex steroids on plasma total homocysteine levels: a study in
administration. A morphologic study. Arch Pathol Lab Med 118:562–565
transsexual males and females. J Clin Endocrinol Metab 83:550 –553
21. Serri O, Noiseux D, Robert F, Hardy J 1996 Lactotroph hyperplasia in an
36. Giltay EJ, Gooren LJ, Toorians AW, Katan MB, Zock PL 2004 Docosahexae-
estrogen treated male-to-female transsexual patient. J Clin Endocrinol Metab
noic acid concentrations are higher in women than in men because of estrogenic
22. Pritchard TJ, Pankowsky DA, Crowe JP, Abdul-Karim FW 1988 Breast cancer
37. Giltay EJ, Gooren LJ, Emeis JJ, Kooistra T, Stehouwer CD 2000 Oral, but not
in a male-to-female transsexual. A case report. JAMA 259:2278 –2280
transdermal, administration of estrogens lowers tissue-type plasminogen ac-
23. Ganly I, Taylor EW 1995 Breast cancer in a trans-sexual man receiving hor-
tivator levels in humans without affecting endothelial synthesis. Arterioscler
mone replacement therapy. Br J Surg 82:341
24. Burcombe RJ, Makris A, Pittam M, Finer N 2003 Breast cancer after bilateral
38. Giltay EJ, Elbers JM, Gooren LJ, Emeis JJ, Kooistra T, Asscheman H, Ste-
subcutaneous mastectomy in a female-to-male trans-sexual. Breast 12:290 –
houwer CD 1998 Visceral fat accumulation is an important determinant of
PAI-1 levels in young, nonobese men and women: modulation by cross-sex
25. Van Kesteren P, Meinhardt W, van der Valk P, Geldof A, Megens J, Gooren
hormone administration. Arterioscler Thromb Vasc Biol 18:1716 –1722
L 1996 Effects of estrogens only on the prostates of aging men. J Urol 156:
39. Elbers JM, Asscheman H, Seidell JC, Megens JA, Gooren LJ 1997 Long-term
testosterone administration increases visceral fat in female to male transsex-
26. Goodwin WE, Cummings RH 1984 Squamous metaplasia of the verumonta-
uals. J Clin Endocrinol Metab 82:2044 –2047
num with obstruction due to hypertrophy: long-term effects of estrogen on the
40. Giltay EJ, Gooren LJ, Emeis JJ, Kooistra T, Stehouwer CD 2000 Oral ethinyl
prostate in an aging male-to-female transsexual. J Urol 131:553–554
estradiol, but not transdermal 17-estradiol, increases plasma C-reactive pro-
27. Van Haarst EP, Newling DW, Gooren LJ, Asscheman H, Prenger DM 1998
tein levels in men. Thromb Haemost 84:359 –360
CONVENCIÓN INTERNACIONAL CONTRA EL DOPAJE EN EL DEPORTE CONVENCIÓN INTERNACIONAL CONTRA EL DOPAJE EN EL DEPORTE La Conferencia General de la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura, en adelante denominada “la UNESCO”, en su 33ª reunión, celebrada en París, del 3 al 21 de octubre de 2005, Considerando que el objetivo de la UNESCO es cont