[A Case of Breast Cancer in a Female-to-Male Transsexual during Androgen Therapy].

ABSTRACT

Gender identity disorder is defined as a condition in which physical and mental sexuality do not match. A female-to-male (FTM)has the mental sexuality of males and the physical sexuality of females. FTM transsexuals generally receive androgen therapy, mastectomy, and sex reassignment surgery to live as their desired sex. The risk of breast cancer in FTM transsexual patients remains unclear. We report a case of breast cancer in an FTM transsexual. A 44-year-old man who underwent mastectomy and sex reassignment surgery and received androgen as hormone therapy developed breast cancer. At first glance, mastectomy and sex reassignment surgery may reduce the risk of breast cancer by suppressing estrogen. However, there are reports of breast cancer in FTM transsexuals. It is important to provide sufficient information that patients may develop breast cancer from residual breast tissue and that they should therefore start hormone therapy even if they have undergone mastectomy and sex reassignment surgery. In order to decide whether to restart androgen therapy after breast surgery, it is necessary to consider not only the risk of recurrence of breast cancer but also their gender identity.