Transgender women increase their risk of getting breast cancer by taking hormones, research suggests.
People who were born male but take oestrogen to transition to a women are more likely to get breast cancer than men.
Meanwhile, transgender men lower their risk of breast cancer by taking testosterone, a study has revealed.
The research follows previous studies which have shown that hormone replacement therapy (HRT) increases the risk of breast cancer in menopausal women.
The study, published in the British Medical Journal, suggested hormone treatment could similarly increase risk of breast cancer among transgender women.
Breast cancer is the most common cancer in the UK, with over 55,000 women and 400 men diagnosed each year.
Scientists at the University Medical Centre in Amsterdam investigated rates of breast cancer in nearly 3,500 transgender people receiving hormone treatment compared with the general Dutch population.
Of the 2,260 transgender women they looked at, 15 were diagnosed with invasive breast cancer – a higher rate than the general male population.
DOES HORMONE THERAPY WHEN TRANSITIONING AFFECT FERTILITY?
Transgender people who were born female and are transitioning to have more masculine characteristics may want to consider freezing their eggs before starting testosterone treatment.
Testosterone suppresses fertility and can leave people completely infertile over time. The hormone does this by stopping eggs being released from the ovaries.
Those who would like to one day have biological children should consider freezing their eggs before starting testosterone treatment or having surgery.
Genital reconstruction surgery – such as the removal of the ovaries, womb or fallopian tubes – may prevent them having biological children unless they use a surrogate.
In 1,229 transgender men, there were four cases of invasive breast cancer – a lower rate than among the general female population.
The authors concluded: ‘The absolute overall risk of breast cancer in transgender people remains low and therefore it seems sufficient for transgender people using hormone treatment to follow screening guidelines as for cisgender people.’
Research suggests a link between HRT and breast cancer.
The most recent figures show women aged 50 to 59 have a 23 in 1,000 chance of getting breast cancer, but for those taking combined HRT, there’s a 28 in 1,000 chance.
Adults who suffer gender dysphoria – a mismatch between their biological sex and gender identity – are offered hormone therapy.
Transgender women who were born male take oestrogen, which reduces their body hair and causes breasts to grow.
Transgender men take testosterone which causes them to build muscle and have more body and facial hair. (DailyMail)