Sexual health outcomes in sexual minority vs. heterosexual men after prostate radiotherapy

Background: The impact of prostate cancer treatments on sexual health outcomes in sexual minority men (SMM), especially in those who engage in receptive anal intercourse (RAI), remains an underrepresented area of scientific investigation. Additionally, limited data exist on differences between treatment-related sexual dysfunction in SMM and heterosexual men (HET). Methods: We conducted an exploratory retrospective analysis of a cohort of sexually active cancer survivors with intact prostates who were seen at least 6 months post-radiotherapy (RT), completed androgen deprivation therapy (ADT), and presented for follow-up between 6/2022 and 8/2023. Patients self-reported sexual orientation, gender identity, sex at birth, sexual behaviors, and PROMIS SexFS scores for orgasm ability, orgasm pleasure, sexual satisfaction, and anal discomfort domains. Average PROMIS scores were compared to the U.S. general population of adult men normative standard scores and between subgroups with mean differences [MD] and t-tests. We considered MD. 3 points to be clinically meaningful. SHIM scores were dichotomized to erectile dysfunction (,16) and function (.17), and analyzed with logistic regression at baseline, 1-, and 2-years post-RT. Results: Of eligible HET and SMM, 39% HET (n=57/145) and 68% SMM (n=21/31) were sexually active with a partner (p=0.005); including 15 (71%) SMM who reported engaging in RAI. Overall, 8% were treated with brachytherapy, 46% external beam radiotherapy, and 46% both; 14% of patients received ADT. Median age was 66 years (interquartile range [IQR]: 61, 71), and median time to survey was 1.3 years (IQR: 0.9, 3.3). The cohort reported worse orgasm function (MD: 3.3, [95% CI: 0.9, 4.7], p,0.01), orgasm pleasure (MD: 7.2, [95% CI: 5.3, 9.1], p,0.001), and satisfaction (MD: 3.4, [95% CI: 1.9, 4.9], p,0.001) compared to norms. Very few demographic or outcome differences were observed between SMM and HET. SMM were more likely to be single (71%) than HET (33%, p,0.005). No differences in erectile function were observed between HET and SMM engaging in insertive intercourse. However, sexually active SMM engaging in RAI reported clinically meaningful differences in orgasm ability (MD: 3.5, [95% CI: -2.9, 9.9], p=0.1), orgasm pleasure (MD: 6.3, [95% CI: 5.2, 9.2], p=0.05), and anal discomfort (MD: 9.0, [95% CI: -0.9, 18.9], p=0.06) but not in satisfaction compared to norms. No clinically meaningful differences were observed by radiation modality. Conclusions: Prostate RT impacts sexual function in HET and SMM. However, the distinct health concerns of SMM and the unique functional anatomy involved in RAI underscore the need for prostate cancer clinicians and researchers to include RAI in sexual outcomes, collect data specific to SMM, and develop targeted interventions for this historically neglected cohort. Research Sponsor: Conquer Cancer, the ASCO Foundation.