Standard practice prior to performing a masculinizing mastectomy in transmales is to review the patient’s personal and family history of breast and other cancers. A detailed history should also include any previous breast surgery, skin changes, nipple discharge, or palpable masses. Any account of familial cancers should prompt referral to a geneticist for additional testing and risk stratification. Essentially, the reconstructive surgeon should have a comprehensive understanding of any predisposition to developing breast cancer such that appropriate screening is performed. High-risk patients (i.e., BRCA positive) should meet with a breast surgeon to discuss whether a risk reduction prophylactic mastectomy is indicated and further delineate long-term monitoring. In patients with a lifetime risk of 20% or greater, the American Society of Breast Surgeons recommends screening with MRI (1). Therefore, transmen that meet this criterion would qualify for screening MRI postoperatively from masculinizing chest surgery as well. This example underscores the importance of including a breast surgeon and/or breast oncologist in preoperative planning in high-risk individuals.

Additionally, the surgeon should comply with national guidelines for breast cancer screening (2,3). Current recommendations include annual mammography starting at 50 years of age in women with no additional risk factors. However, certain high-risk patients qualify for earlier screening and this should be evaluated on a case-by-case basis. Prior to performing mastectomy, it is incumbent that appropriate screening is performed and reviewed by the surgeon. Any abnormalities warrant further workup prior to proceeding with GAS. In addition to screening for breast cancer, a detailed breast and axillary examination is necessary in all patients to evaluate for masses, skin changes, and/or nipple aberrancies. Any evidence of abnormality warrants further evaluation by a breast oncology surgeon prior to GAS.

The incidence of breast cancer in genetic males is quite low, around 0.1%. Therefore, no specific screening recommendations are in place for detection of breast cancer in males. However, transwomen are oftentimes on feminizing hormone therapy including estrogen, progesterone, and testosterone blockers. The surgeon should document all past history and current medications, especially hormone therapy (including duration of treatment and adverse effects). The long-term effects of these medications on glandular development, specifically glandular dysplasia, warrant screening guidelines for patients receiving
hormone therapy (4,5). A Dutch study published in May 2019 presented a significantly increased risk of breast cancer in transwomen on hormone treatment. Specifically, a 46-fold increased risk of breast cancer exists compared to cis-gender men. In this cohort, the median duration of hormone therapy was 15 years and the majority of tumors were both estrogen and progesterone sensitive, and of ductal origin (6). These features suggest that although the increased risk of breast cancer in transwomen is lower than cis-gender women, hormone therapy likely plays a critical role in the pathogenesis of breast cancer in transfemales.

To encompass both the risk of hormone therapy and general population recommendations for cis-gender women, screening mammography for transfemales is recommended every 2 years for patients older than 50 with at least 5 years of hormone therapy (7). As with cis-gender women, additional risk factors may prompt lowering the age at which to initiate screening. Family history or known mutations should warrant genetic counseling to guide decisions on screening frequency and modality. Although mammography is still the modal examination utilized, certain patients may require an MRI (8). Lastly, it is important to note that transwomen although have a lower incidence of breast cancer compared to cis-gender women, the average age of disease is lower in the transwomen population (6). This data warrants a discussion regarding lowering the age at which we recommend screening mammography in patients on hormone therapy.