Breast cancer risk in transgender people: the value of gaining new insights from other sources
Menée aux Pays-Bas à partir de données portant sur 3 489 personnes transgenres (2 260 femmes nées de sexe masculin et 1 229 hommes nés de sexe féminin), cette étude analyse le risque de cancer du sein en lien avec les traitements hormonaux reçus et leur durée d'exposition (durée médiane du traitement hormonal chez les femmes transgenres : 18 ans et 15 cas ; durée médiane du traitement hormonal chez les hommes transgenres : 15 ans et 4 cas)
Few studies have investigated the incidence of breast cancer in transgender people. [1,2] The studies that have been done were retrospective, owing to the fact that it takes a while before the side effects of hormone treatment can reliably be studied. Although these studies provide new information about the risk of developing breast cancer for transgender people, the researchers encountered some obstacles for which they were unable to account for. For instance, transition status was not always clearly stated in the registries used, potentially leading to unnecessary exclusion of suitable participants. Other studies struggled with the fact that transgender people were treated in different healthcare centres for diagnosis other than gender dysphoria. This has often led to an underestimation of incidence numbers. Some of the studies lost a large number of people at follow-up. When we were planning our recent study investigating breast cancer risk in transgender people, we struggled with some of these obstacles as well. Even though our healthcare centre provides transgender healthcare to more than 95% of all transgender people in the Netherlands, many of our study participants were lost to follow-up, especially those who started their treatment decades ago. Although the Netherlands is a small country, it has a lot of hospitals. Transgender healthcare is mostly centralized and performed in our centre, but other healthcare, including breast cancer diagnosis and treatment, is carried out in local hospitals. As we wanted to obtain as much data as possible about the people in our cohort, we started searching for other ways to gain the information that we needed. [3]