Nice post Northern Jane....
Anyway, an acceptable study for this conversation
http://jcem.endojournals.org/content/93/1/19.full.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. (That's a lot of data there.)
Conclusions
It is now clear that sex reassignment of transsexuals benefits their well-being, (33) although suicide rates remain high (7). Regrets are rare (0.5–3.0%). Cross-sex hormone administration to transsexuals is acceptably safe in the short and medium term. However, potentially adverse effects in the longer term are presently
unknown. The data, although limited, of surrogate markers of cardiovascular disease and the reports of cancer in transsexuals leave room for a
cautious optimism. But true insight can only come from close monitoring and thorough reporting of adverse effects in the literature.
OK – They don't know. It means not enough data to say it is bad but also not enough to say there isn't an effect. That's very different from saying it's bad.
My Read - There is some conflicting data, particularly from trans folks treated in the 70's and 80's, where the doses and types of treatment were varied. Treatment is much more developed now and presumably, adverse effects will be lessened.
Comparing the effects of antiandrogens on prostate cancer patients with healthy trans women is very error prone. At best it can lead to an insight and cannot be definitive. At worse, it can lead to erroneous conclusions. Antiandrogens may pose a risk – this is unknown.
For the trans men, the once proposed increases risk for ovarian cancer is actually much less that thought and up regulation of androgen receptors is expected. However, there is no data to show this is a problem. It's an observation. Our bodies up regulate all kinds of receptors in response to a number of exposure scenarios such as medication and diet.
The breast cancer risk for a MTF – appears low but might be more than if there were no treatment. The data cannot support an increased risk vs. natal females. We need to have regular mammograms, they don't hurt that much.
However, there still may be a risk for FTM's as some breast tissue may still remain after surgery (guys, should be informed about that before, during and after top surgery.)
Cardiovascular risk – life style has a big impact and has not been controlled in the studies. Adopt a healthy life style.
A slightly different read from me: No measurable effect from HRT on transgender people. Lifestyle plays a bigger role.
I HATE, HATE, HATE bad science and people who promote bad science to support a preconceived bias. If someone doesn't like trans folks, well, they can be stupid if they want to be stupid. But don't scare people by spreading manure disguised as scientifically valid studies.
