Transgender and non-binary patients using hormone therapy may need endometrial thickness assessment as part of their transgender healthcare plan.
An excessively thick endometrium, or endometrial hyperplasia, is a known risk factor for endometrial cancer. According to the American Cancer Society, cancer of the endometrium is the most common cancer of the female reproductive organs in the United States. About 66,200 new cases of endometrial cancer and uterine sarcomas were diagnosed in 2023. Physicians can use transvaginal and transabdominal ultrasound to diagnose endometrial thickening, which can catch the condition before it progresses to cancer.
Endometrial hyperplasia occurs as a result of chronic exposure to estrogen paired with a relative deficiency of progesterone. This imbalance may result from hormonal changes, from estrogen replacement therapy or from medications used as cancer treatment. Other risk factors for endometrial hyperplasia include age (occurring most often in menopausal cisgender women), never having given birth, genetic history of gynecologic cancers, and comorbid conditions (such as obesity, diabetes, polycystic ovarian syndrome and ovarian cancer). Endometrial thickness could be a transgender healthcare concern for transgender men who retain a uterus and have other risk factors associated with the condition.
Ultrasound Imaging Techniques to Measure Endometrial Thickness
The American College of Obstetricians and Gynecologists (ACOG) says that vaginal bleeding is the presenting symptom in more than 90% of postmenopausal women with endometrial carcinoma and that transvaginal ultrasonography is an appropriate sonographic tool to rule out carcinoma in that patient group. However, an OB/GYN may need to choose alternate imaging techniques when caring for transgender patients. If a transgender male patient who retains a uterus presents with vaginal bleeding and other endometrial cancer risk factors, the prospect of a transvaginal ultrasound could exacerbate their sense of gender dysphoria. A transabdominal ultrasound can be used if a trans male or non-binary patient does not prefer a transvaginal ultrasound. Fertility and Sterility published results of a study that found abdominal ultrasound measurement of endometrial thickness is as accurate as vaginal ultrasound measurement.
The Role of Hormone Therapy in Determining Cancer Risk in Transgender Patients
Some transgender and non-binary patients may use gender-affirming hormone therapy (GAHT). Masculinizing hormone therapy prompts masculine physical characteristics through the use of testosterone. Feminizing hormone therapy is used by trans women and non-binary people and prompts feminine physical characteristics through the use of estrogen. According to Translational Andrology and Urology (TAU), GAHT complicates determining the risk of sex-specific cancers. TAU concludes that current evidence does not show a greater cancer risk due to GAHT, while noting that evidence is limited and more research is needed. They further affirm that hormone therapy does not remove the chance of developing cancer in a person's natal sex organs, and that transgender people still need to follow cancer screening recommendations for all organs present in their bodies regardless of their transition status. TAU recommends that transgender people and their physicians follow established screening guidelines and base these screenings on present anatomy, risk factors, and high-risk behaviors that can affect cancer risk.
The Challenges of Ultrasound Imaging Techniques for Transgender Patients
Transgender and non-binary people may adjust social characteristics to match their gender identity (their psychological, inner sense of gender), such as their clothing, hairstyle, pronouns, and name use, while retaining their natal sex organs. Some may also use hormone medications and/or surgery to physically align their bodies to their gender identities. OB/GYNs may encounter patients spanning the gender spectrum. As a result, physicians need to know how to address the physical and psychological challenges that transgender patients may face during an ultrasound assessment.
As mentioned above, some gynecologic care and ultrasound techniques may create a sense of gender dysphoria, where a person's sex at birth does not match their psychological sense of gender. For that reason, a non-binary person or trans male may hesitate or even refuse transvaginal ultrasound. Gynecologists should continue engaging in open and respectful discussions with patients to explain why an assessment is needed and what to expect during the procedure. They should also be aware of reasonable imaging alternatives that may be more acceptable to the patient, such as a transrectal or transabdominal ultrasound for assessing endometrial thickness.
Interpretation of Results and Clinical Decision-Making
Physicians use transvaginal ultrasound to measure endometrial thickness and to determine causes of abnormal uterine bleeding (AUB). Those measures help gauge the likelihood of endometrial cancer. Postmenopausal cisgender women use hormone replacement therapy (HRT) to treat symptoms of menopause, which can cause postmenopausal bleeding. If a person of postmenopausal age has AUB but a thin endometrium (under 4 to 5 mm), then endometrial cancer can be ruled out as the cause. Changing dosages or medications used for HRT may stop the bleeding. If there is AUB and a thick endometrium, then more detailed imaging (such as a CT or MRI) should be scheduled because a diagnosis of endometrial cancer is more likely.
Trans and non-binary persons may use hormone therapy for gender-affirming care, but that is different from HRT. According to UCSF Transgender Care, most transgender men will experience endometrial atrophy, not hyperplasia, when on testosterone hormone therapy. However, trans men who experience AUB need to tell their provider so they can discover the cause.
Transvaginal and transabdominal ultrasound are essential tools that may come into play in transgender healthcare. As OB/GYNs recommend cancer screenings to patients, they need to be prepared for the challenges that transgender patients may face. This includes physical and psychological hurdles, as well as the roles that family history, hormone therapies, and risk factors may play in a well-rounded transgender healthcare plan.
