Gender-affirming hormonal treatment (HT) in transgender people is considered safe in general, but the question regarding (long-term) risk on sex hormone-related cancer remains. Because the risk on certain types of cancer differs between men and women, and some of these differences are attributed to exposure to sex hormones, the cancer risk may be altered in transgender people receiving HT. Although reliable epidemiologic data are sparse, the available data will be discussed in this article. Furthermore, recommendations for cancer screening and prevention will be discussed as well as whether to withdraw HT at time of a cancer diagnosis.