According to Cancer Research UK, breast cancer is the most common type of cancer in the UK, accounting for 15% of all cases of cancer in both men and women. The Daily Mail states that 55,000 women and 400 men are diagnosed each year.
Previous studies have demonstrated that hormone replacement therapy used to alleviate severe menopausal symptoms can incease the risk of breast cancer. This was followed by a research that was posted in the British Medical Journal about the increased likelihood of transgender women getting breast cancer. On the other hand, transgender men who take testosterone decrease their risk [R].
Several scientists at the University Medical Centre in Amsterdam looked into the rates of breast cancer in transgender people compared to the general Dutch population.
They looked at 2,260 transgender women, of which 15 were diagnosed with invasive breast cancer. This rate is higher than the general male population. On the other hand, they also looked at 1,229 transgender men and noted 4 diagnosed with invasive breast cancer, which is a rate that is lower than the general female population [R].