Importance: Transgender and gender-diverse individuals face unique challenges, including barriers to health care access and inequities in treatment, that may influence cancer risk and outcomes. Observations: In this narrative review, a scoping review was conducted focusing on primary and secondary prevention and epidemiology of cancer, barriers to health care services, and health care practitioners' knowledge about specific issues pertaining to transgender and gender-diverse individuals. PubMed, the Cochrane Library, and Embase, were reviewed for citations from their inception to December 31, 2021. This review revealed that transgender and gender-diverse people had a high prevalence of tobacco consumption and alcohol use and high rates of infection with human papillomavirus (HPV) and HIV. Transgender and gender-diverse individuals were less likely to adhere to cancer screening programs and had a higher incidence of HIV- and HPV-associated cancers. Social and economic determinants seemed to drive these disparities in risk factors and outcomes. A lack of knowledge about gender minorities' health needs among health care practitioners was evidenced, and it represented a major hurdle to cancer prevention, care, and survivorship for transgender and gender-diverse individuals. Discrimination, discomfort caused by gender-labeled oncological services, stigma, and lack of cultural sensitivity of health care practitioners were other barriers met by transgender and gender-diverse persons in the oncology setting. Conclusions and Relevance: The findings suggest that transgender and gender-diverse peoples' needs in the cancer care continuum are not optimally addressed. Effective solutions are needed to offer the best care to every patient in a person-centric and gender diversity-sensitive environment.