Hereditary Cancer in Transgender Men

Gender-affirming hormones and breast cancer risk

Transgender men may choose to take testosterone as part of gender-affirming hormonal care. Very little research has been done on the effects of hormonal therapy for high-risk transgender men. Some research suggests that testosterone may reduce the amount of glandular tissue in the breast, which could protect against breast cancer. More research is needed to understand whether or not testosterone is protective in high-risk trans men, and if so, how much. 

Top surgery vs. risk-reducing mastectomy

Mastectomy is the surgical removal of breast tissue. Most mastectomies, even radical mastectomies leave behind some breast tissue. For people at high risk for breast cancer, mastectomy significantly lowers the risk. The remaining risk after mastectomy depends on how much tissue is left behind.  

Risk-reducing mastectomy is a procedure that  lowers the chance of developing breast cancer in people with high risk. The goal of risk-reducing mastectomy is to remove as much breast tissue—and as much risk—as possible. 

The goal of top surgery for transgender men and nonbinary people is to provide a more masculine-appearing chest. Similar to risk-reducing mastectomy, top surgery removes breast tissue. However, it often leaves more breast tissue behind to provide a more natural-looking chest. 

For transgender men with a mutation that significantly increases breast cancer risk, standard top surgery leaves more breast tissue than a risk-reducing mastectomy. This residual tissue and its associated cancer risk, however, may be unacceptable for high-risk trans men. A mammogram and breast MRI before surgery may help rule out the possibility of cancer and aid in the decision-making process. For high-risk men who have had top surgery, see below for information about annual screening.  

Regardless of the type of surgery chosen, it's important for high-risk trans men who are considering top surgery to consult with a surgeon who has knowledge of hereditary cancer risk, so that they can discuss different surgical options and how much breast tissue to remove. 

All high-risk trans men who have top surgery should speak with their surgeon to ensure that their breast tissue will be reviewed by a pathologist who will carefully check it for any signs of cancer.

Breast screening before surgery

For transgender men who have not had top surgery, screening guidelines are the same as cisgender women. These guidelines vary by gene, but they usually include regular breast exams by a doctor, as well as an annual mammogram and breast MRI. Trans men should be aware of any changes in their chest and report any abnormal findings to their doctor. 

Breast screening after surgery

National guidelines do not recommend routine screening for high-risk cisgender women after risk-reducing mastectomy, which removes as much breast tissue as possible. . There is very little research on the benefits of screening after top surgery for high-risk transgender men. High-risk trans men should have a conversation with their surgeon about screening after top surgery, which should take into account the amount of breast tissue that remains.  

Risk-reducing gynecologic surgery

National guidelines recommend risk-reducing surgery to remove the ovaries and tubes (salpingo-oophorectomy) for people at high risk for ovarian cancer. The recommended age for surgery varies by gene. These guidelines also discuss the option of hysterectomy (removal of the uterus) for people at high risk for endometrial or uterine cancer. The surgeries can be done at any time, but for people who wish to become pregnant, the recommendation is to wait until after childbearing is complete.

Bottom surgery for transgender men generally includes creating a more masculine appearance of the external genitalia. Bottom surgery may also include removal of the female reproductive tract, including the ovaries and fallopian tubes (salpingo-oophorectomy) and uterus (hysterectomy). If you are a trans man considering bottom surgery, it's important that you know your risk for these cancers. There is no reliable early detection for ovarian or fallopian tube cancer. For this reason, removal of the ovaries and fallopian tubes is recommended for people with a high risk for these cancers.

Some research suggests that risk-reducing salpingo-oophorectomy may also lower the risk for breast cancer, especially for people with BRCA2 mutations. 

Gynecologic cancer screening

For transgender men who have not had a hysterectomy or salpingo-oophorectomy, screening guidelines are the same as for cisgender women. High-risk trans men should be aware of the signs and symptoms of endometrial and ovarian cancer. 

There is no accurate early detection test for ovarian cancer. For this reason, national guidelines do not recommend routine screening for high-risk people. For people who have chosen risk-reducing salpingo-oophorectomy, CA-125 and pelvic ultrasound may be used before surgery to rule out cancer.

Endometrial cancer can often be detected early due to symptoms, such as abnormal bleeding. For people at high risk for endometrial cancer, transvaginal ultrasound and endometrial biopsy may be an option for endometrial cancer screening. Guidelines suggest that high-risk individuals have a conversation with their doctor about the benefits, risks and costs of endometrial cancer screening.