JOHNSON CITY, TN – Consistent with past European studies, new research from the Mountain Home VAMC suggests that transgender (TG) veterans have no higher rates of breast cancer than others.

The study, published recently in the journal Breast Cancer Research and Treatment, notes that cross-sex hormones (CSH) often are used as part of the treatment plans for the transgendered, but little is known about the incidence of breast cancer in that group.1

“This information gap can lead to disparities in the provision of transgender healthcare,” according to the authors who said their study used the North American sample of TG patients studied to date to determine their exposure to CSH, incidence of breast cancer, and to compare results with European studies in transsexual populations.

For the study, researchers used VHA data from 5,135 TG veterans in the United States from 1996 to 2013 to determine the incidence of breast cancer in this population, with chart reviews completed on all patients who developed breast cancer. In addition, age-standardized incidences of breast cancer from the general population were used for comparison, and person-years of exposure to known CSH treatment were calculated.

Most of the patients, 52%, received more than one dose of CSH treatment from VHA clinicians, according to the study.

Overall, 10 breast cancer cases were confirmed, with seven in female-to-male patients, two in male-to-female patients and one in a natal male with transvestic fetishism. The average age at diagnosis was 63.8. Breast cancer was fatal in all three male patients, who presented with late-stage disease.

The overall incidence rate was 20.0/100,000 patient-years of VHA treatment, irrespective of VA CSH treatment.

“This rate did not differ from the expected rate in an age-standardized national sample but exceeded that reported for smaller European studies of transsexual patients that were longer in duration,” the authors write. “Although definitive conclusions cannot be made regarding breast cancer incidence in TG veterans who did or did not receive VA CSH due to the sample size and duration of observation, it appears that TG veterans do not display an increase in breast cancer incidence.”

They add that the findings are “consistent with European studies of longer duration that conclude that CSH treatment in gender dysphoric patients of either birth sex does not result in a greater incidence than the general population.”

Brown GR, Jones KT. Incidence of breast cancer in a cohort of 5,135 transgender veterans. Breast Cancer Res Treat. 2015 Jan;149(1):191-8. doi: 10.1007/s10549-014-3213-2. Epub 2014 Nov 27. PubMed PMID: 25428790.