Abstract Background: Recent U.S. estimates show 20 million+ people identify as two-spirit, lesbian, gay, bisexual, transgender, queer, intersex, or asexual (2SLGBTQIA+). Despite heightened risk factors for cancer, 2SLGBTQIA+ people are an underserved population and have rarely been included in cancer research. Further, cancer-related mortality and quality of life measures for this population remain unknown. The Elsie Study uses in-depth interviews to better understand the experiences of 2SLGBTQIA+ people who have been treated for cancer and explore recruitment considerations to improve their research participation. Methods: We conducted 60-90 minute one-on-one semi-structured interviews with 2SLGBTQIA+ adults who have been previously treated for cancer. We recruited participants through targeted creative advertising campaigns on dating apps (HER, Scruff, Jack’d, Grindr) and through community organizations, community events, and the study website. Questions explored cancer treatment experiences, intersectional identities and experiences, research participation decision-making, recruitment strategies, and trusted sources of information. We recorded, transcribed, and de-identified interviews, and used thematic approaches for qualitative analysis. Results: Between June 2023-June 2024, we completed 65 interviews with sexually diverse cisgender women (n=17), cisgender men (n=16), transgender women (n=11), transgender men (n=4), and nonbinary, gender-expansive, and two spirit people (n=17). Participants were located throughout the U.S. in rural and urban areas with differing levels of cancer treatment access, social support, and structural support. Participants were treated for many types of cancer, with the most common being breast, prostate, and blood cancers. Among the sample, 38.5% were American Indian or Alaska Native, African American, or Asian/Asian American, and 13.8% identified as Hispanic. Notably, racially/ethnically marginalized 2SLGBTQIA+ participants described the emotional toll of dehumanization and how it impacted their cancer care treatment as individuals with multiple marginalized identities. For example, one participant said “Although I’m going through this physical pain, it’s emotionally painful to have to explain myself and my identifications to people who don’t know and don’t want to know either… What’s the point?” Another participant said, “When people don’t look at you as human, then it’s down from there unfortunately."Most participants had not previously participated in health research, but all interviewees affirmed they wanted to know the results from the study and wanted to be notified about future research opportunities with our team. The use of dating apps and community organizations as recruitment methods was noted as novel and trustworthy. Conclusion: People of all genders and sexual orientations get cancer, and 2SLGBTQIA+ people represent an increasing number of oncology patients. It is imperative that the perspectives of 2SLGBTQIA+ people be considered in cancer care and cancer research. Citation Format: Alexandra M. Ecklund, Ben Weideman, Rhea Alley, Courtney Sarkin, B.R. Simon Rosser, G. Nic Rider. “When people don’t look at you as human, then it’s down from there…”: Experiences of 2SLGBTQIA+ people treated for cancer and implications for research participation [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B118.