NEW YORK—Cancer screening in transgender people may sometimes require a modified approach to current guidelines, according to researchers at a meeting here at Memorial Sloan Kettering Cancer Center focused on cancer in lesbian, gay, bisexual, and transgender (LGBT) communities. In addition, speakers noted, patients may also have to contend with obstacles to culturally competent cancer care, as indicated by survey results from the Cancer's Margins project of the University of British Columbia.
Little Research Available
Only a limited body of research is available concerning the biomedical aspects of cancer care for transgender patients, said Evan Taylor, MSW, a doctoral student in the Centre for Cross-Faculty Inquiry in the Faculty of Education Program at the University of British Columbia and Research Assistant for Cancer's Margins.
Although some case studies have pointed to an increased cancer risk from hormone treatments in transgender populations, this has not been definitively addressed in large trials, he noted. Case studies also recommend modifications to some routine cancer screenings, he said.
Another speaker, Ronica Mukerjee, FNP, Lac, MSN, MsA, NP, an acupuncturist at Collective Primary Care and the former Director of Transgender Health for Community Healthcare Network in New York, said that because studies of transgender people are lacking, providers generally follow the screening guidelines published by organizations such as the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians and may make modifications based on extrapolated data—for example, studies of postmenopausal women on hormone-replacement therapy.
Cancer Mortality Not Increased
Notably, a 2011 study (Eur J Endocrinol 2011;164:635-642) of 966 male-to-female (MTF) and 365 female-to-male (FTM) individuals, found that there is no increased cancer mortality in these populations, she said. However, the rates of lung cancer were significant higher, possibly due to heavier smoking in these individuals.
“You'll see that trans patients smoke more than the LGB population,” she said. Consequently, health care providers should screen their transgender patients for past or present tobacco use. Poverty, stressful living, and lack of employment are often factors that transgender individuals are coping with and that contribute to the likelihood of smoking.
The rates of hematologic malignancies were also shown to be higher in the 2011 study, and researchers theorized that this might have been due to HIV-associated non-Hodgkin lymphoma.
Screening in FTM patients
Female-to-male transgender people need to receive gynecological pelvic and chest or breast care, Mukerjee continued. For cervical cancer screening in this population, health care providers should follow the guidelines of the American Society for Colposcopy and Cervical Pathology (ASCCP) for Pap smear.
“There's no evidence that testosterone increases or reduces the risk of cervical cancer,” she said. If the patient is low risk based on HPV status, precancerous lesions are also unlikely to be present. However, pathologists may find a higher prevalence of parabasal cells, which are associated with atrophy in postmenopausal women. If patients have undergone a hysterectomy, providers should find out if the cervix was kept. If it was, then a Pap smear needs to be performed.
Physicians and researchers often wonder about an elevated risk of endometrial and ovarian cancer in FTM patients, Mukerjee continued. “There's a lot of unknowns in this area, but we do know that there's no real evidence that taking testosterone leads to endometrial hyperplasia or proliferation.
“What we've seen in the small studies that are out there is that there is an atrophic effect of androgen on the endometrium, and PCOS [polycystic ovarian syndrome]-like changes are more prevalent with testosterone,” she said, citing J Sex Med 2009;6:3193-3200 as one example.
Overall, uterine histology is not very different in this population, except for the lack of proliferation and menstruation, she said. Researchers can extrapolate that if there's not a lot of cells growing, then there is less likelihood that someone is going to get a cancerous growth.
“There is, however, some weak evidence that PCOS may increase ovarian cancer, and with testosterone usage the risk of PCOS is greater,” she said. Additionally, transgender patients older than 40 and with a family history of the disease are also at elevated risk. In general, the USPSTF guidelines for ovarian cancer screening do not extend beyond performing a bimanual examination.
Some physicians may want to recommend a hysterectomy or an oophorectomy as prevention in FTM patients, Mukerjee said, adding that such a recommendation requires a comprehensive conversation with the patient about the procedure's implications—“Still, it might be something that the patient wants.”
For breast cancer screening, the USPSTF guidelines should be followed for natal sex, Mukerjee said. “For patients who have had chest surgery, there's definitely mammary tissue that's left, so doing a chest wall palpation is a good idea on a yearly basis.” Generally, a mammogram is not feasible, but sonogram or an MRI may be useful.
Mhel Kavanaugh-Lynch, MD, MPH, Director of the California Breast Cancer Research Program, said that although some health care providers suspect that long-term testosterone use may elevate breast cancer risk because the hormone may convert to estrogen, specific data in the transgender population are not available to support that theory.
Finally, FTM individuals who are HIV-positive and have an abnormal cervical Pap test or obvious condyloma should be screened for anal cancer with high-resolution anoscopy (HRA) to see if biopsy or removal is needed, said Mukerjee.
Screening in MTF Patients
For MTF patients, “the big question is about prostate cancer screening,” Kavanaugh-Lynch said. There have been case reports of prostate cancer in MTF patients pre- and post-feminizing genital surgery.”
The androgen-blockers that MTF patients may be taking can suppress the growth of prostate cancer cells. However, because the therapy can also suppress prostate-specific antigen, PSA tests are no longer reliable in those who may have prostate cancer. Performing a digital rectal exam and educating all patients older than age 50 about prostate health is critical, she said.
The prostate is not removed with feminizing genital surgery, added Mukerjee. In patients with a neovagina, the prostate needs to be checked anterior to the vaginal wall. “It's not going to be a rectal test anymore for the prostate,” she said.
Breast-screening mammography in MTF patients should occur every one to two years in those over age 50 with additional risk factors, including estrogen and progestin use for more than five years, a positive family history of breast cancer, and a body mass index of more than 35, she said. “Still, there are some people who, of course, say start screening at age 40.”
In MTF individuals the risk of breast cancer is going to be lower, Kavanaugh-Lynch said. However, long-term estrogen use in this population may elevate the risk of breast cancer. Few data are available on incidence, “but it happens and it happens with some frequency,” she said.
Additionally, in MTF patients, because breast implants may make detection more difficult, getting an appropriate mammogram is important, she said.
While breast cancer screening is necessary, Pap tests are not needed in MTF patients because a cervix is not created with vaginoplasty, Mukerjee said. The development of neovaginal condyloma is possible, which is notable because the neovagina is lined with keratinized tissue. However, condyloma are rarely associated with cancer, and overall, “there really have not been many case reports of neovaginal cancers.”
Finally, MTF patients should also be screened for anal cancer with anal Pap smears if patients are HIV positive, Mukerjee said.
Contraindications for Hormonal Treatment
Transgender patients diagnosed with cancer may have to contend with contraindications to their hormone treatment. Testosterone, which can be converted to estrogen, and estrogen therapy are contraindicated in patients with estrogen receptor (ER) positive breast cancer, Mukerjee noted. These hormones may also need to be avoided in patients with ER-sensitive lung cancer, although more research is needed on this topic, she said.
Testosterone-blockers, especially spironolactone, should be avoided in patients with end-stage renal disease, which can come from cancerous causes, she noted.
Patients with transaminases levels three times the above upper limit of normal, which can occur with hepatic cancer, need to be closely monitored if they are receiving hormone therapy, Mukerjee noted. Finally, hormone therapy is contraindicated in patients with uterine cancer.
Minority gender and minority sexuality remain irrevocably linked with health care decision-making and are associated with poorer health outcomes in cancer patients, Taylor said.
Missing from the research literature is information on transgender people's actual lived experiences with cancer, which is part of what the Cancer's Margins research project is trying to address. Preliminary interview data from 62 participants across Canada who identified themselves as queer, gay, lesbian, bisexual, or transgender has offered many insights into the implications of gender and sexual marginality and the need for culturally competent cancer care, Taylor said.
For example, transgender health needs are not being addressed concurrently with cancer care. Oncologists may simply tell the patient to stop taking hormone treatment without talking about transgender health.
Additionally, medical forms are often difficult to fill out due to the male or female delineation, and patients have to constantly negotiate when and where to educate their cancer health care providers about their gender.
Peer support can also be challenging to access for transgender patients, Taylor noted. Often, people running the support groups may not understand the meaning of transgender or gender identification and how it differs from sexual orientation—gender is usually classified as two distinct sexes. She gave the example of one FTM survey participant with ovarian cancer who decided to access a support group, but felt he had hide his gender identity.
Survey responses also indicate that transgender patients' cancer health care decisions are negatively affected by the lack of research data available and the absence of a cancer registry tracking by gender. As a result, information on hormone treatment and cancer risk is not readily available through their health care providers.
The Cancer's Margins project has also found that the “intersectional complexities” of transgender cancer patients need to be considered, Taylor noted. “Transgender people's cancer experiences are shaped by intersectional modes of privilege and oppression, such as gender, socioeconomic status, and racialization.”
Despite the many obstacles, though, she concluded, transgender patients are highly motivated to access cancer health care and transgender health and community support.