Triple-Positive <i>PALB-2</i> Breast Cancer in a 27-Year-Old Male-to-Female Patient.

Breast cancer risk in transgender patients with long-term hormone therapy use is not well understood. Individuals, both male and female, with a family history of breast cancer; increased cumulative lifetime estrogen and progesterone use; or mutations in BRCA1, BRCA2, CHEK2, PTEN, or PALB2 genes have an increased risk for breast cancer. Hormonal treatment is often used alongside gender-affirming surgeries for development of female secondary sex characteristics in male-to-female patients. Although hormone therapy can have gender-affirming benefits, the increased lifetime exposure to estrogen and progesterone can increase the risk of breast cancer. Mammography guidelines for transgender patients vary by age, familial and genetic risk, as well as duration of hormone therapy. Three current organizations have published mammographic screening guidelines for transgender patients: the University of California San Francisco, the World Professional Association for Transgender Health, and the American College of Radiology. Future research should focus on substantiating these guidelines with greater data to produce evidence-based recommendations to guide the care of transgender patients.