Breast cancer in transgender patients: A systematic review. Part 1: Male to female

Abstract

Male-to-Female (MtF) breast cancer events have been reported since 1968 however, MtF patients' risk of breast cancer remain unclear. Following PRISMA guidelines, electronic databases and grey literature were searched April 2018 to identify breast cancer events in MtF transgender persons. Screening and data extraction were independently performed in duplicate by two reviewers. Study quality was assessed using a component-based system. Qualitative analysis was performed on study characteristics, patient demographics, breast cancer characteristics, and breast cancer presentation and management. Eighteen articles met inclusion criteria representing 22 breast cancer events. Median age at breast cancer diagnosis was 51.5 years. The most common breast cancer type was adenocarcinomas (59.1%) and half of the breast cancers were hormone sensitive, with estrogen receptor positive status in 10 of 19 tested and progesterone receptor positive status in 5 of 14 tested. The most common presentation was breast lump (n = 6, 42.9%), two patients had palpable lymph nodes at presentation (14.3%), and six patients eventually developed metastases (42.9%). Seven patients had a recorded positive breast cancer family history and one was BRCA2 positive. Breast cancers were treated with mastectomies (simple, modified radical, and radical), wide local excision, lumpectomy, or were unclear. Four patients received hormone therapy (23.5%), two received radiation (11.8%), and seven received chemotherapy (41.2%). Breast cancer is present in MtF patients and commonly presents at a younger age with a palpable mass. Major gaps in the literature include lack of transgender population data and long term follow-up. This work highlights the need for screening recommendations.

Breast cancer risk in transgender people receiving hormone treatment: nationwide cohort study in the Netherlands

“…To date, 22 cases of breast cancer in trans women and 20 cases in trans men have been published. 16 17 18 19 However, reliable estimations of the risk in transgender people are lacking because of the heterogeneity in the population and study cohorts. 20 …”

Triple Negative Breast Cancer in a Male to Female Transgender Patient: A Case Report and Literature Review

“… 11 , 19 In addition, the review by Hartley et al, which included transgender female patients, demonstrated that only 13.6% of patients who received a diagnosis based upon screening mammography. 17 Albeit a small sample size, this rate is significantly less than the 43% rate seen in cisgender women. 20 Thus, although the “Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People” from University of California, San Francisco generally recommends beginning at age 50, the aforementioned information and the lack of randomized evidence illustrates that it is not entirely clear when initiating screening mammography is most appropriate.…”

“…According to a recent review, transgender female who received a diagnosis of breast cancer tended to be diagnosed at a younger median age (51.5 years) compared with both cisgender female (60 years) and cisgender male (68 years) patients. 17 This suggests that transgender female patients may benefit from screening beginning at a younger age than their cisgender female counterparts, which is typically recommended starting at age 50. 18 However, according to 2 cohort studies in transgender women, the incidence of breast cancer in this population remains low, between 4.1 and 20 per 100,000 patient years, compared with cisgender females, in whom the incidence is as high as 170 cases per 100,000 patient years.…”

Breast cancers, mammary stem cells, and cancer stem cells, characteristics, and hypotheses

“…Albeit studies remain scarce, the same discrepancy is observed for transgender male to female, where breast cancer is usually diagnosed at a younger age 51.5-year old while the incidence of breast cancer is increased by 46-fold when compared to male [13 , 14] . The transition from male to female relies on antiandrogens and estrogen therapies, which increase the risk of breast cancer [14] . A younger age of diagnosis at 44.5 years of age is also observed for individuals transitioning from female to male [15] .…”