The same study shows that this risk is lower for transsexual men than for women.
Transsexuality does not necessarily involve surgery, but many transsexual people receive hormone therapy.
One expert notes, however, that this increased risk is only apparent in the short term, and in the long term appears to be slightly lower than in the general population.
"When you look at a long-term perspective, there's still a comfort to the people who are going to this process," says Dr. t Réjean Lapointe, Scientific Director of the Montreal Cancer Institute. They don't have to worry too much. "
A transsexual person identifies with a different sex to the one assigned at birth. A transsexual woman is born with male reproductive organs, and the back for a transsexual man, but does not necessarily identify with sex.
Researchers at the University Medical Center in Amsterdam studied 2260 women and 1229 transsexual men who were treated in a city clinic between 1972 and 2016. They found 15 cases of breast cancer in transsexual women, 18 years on average. hormonal treatment.
This rate is higher than that of the general male population whose gender corresponds to that attributed to birth, but below the overall female population.
Four cases were also found among the 1229 transsexual men, an average of 15 years after the onset of hormone therapy. This rate is also lower than the overall female population rate.
"I don't think there's a case for an alarm," said Dr Lapointe, who also pointed out that only a few thousand people came together in this study. It is still low as the number of cases. Nothing in this study could trigger a master alarm signal. "