Abstract Introduction: Genitourinary syndrome of menopause (GSM) is a common yet underrecognized effect of endocrine therapy leading to sexual dysfunction in breast cancer survivors. Vaginal hormones are the most effective treatment but are infrequently prescribed due to concerns regarding systemic absorption. Platelet-rich plasma (PRP) is derived from a patient’s blood and centrifuged to remove erythrocytes, and the concentrated growth factors promote tissue repair, angiogenesis, and collagen synthesis. It is unknown whether PRP, created and applied in a standardized approach, could improve vulvovaginal symptoms in patients on estrogen suppressive therapies. This phase II trial sought to determine whether 2 vulvovaginal PRP treatments could constitute a novel GSM therapeutic for breast cancer patients with GSM. Methods: A prospective phase II pilot trial included female breast cancer patients with GSM treated with two sessions of PRP one month apart. 4cc of PRP was created from 30cc of whole blood collected by venipuncture using the Magellan Autologous Platelet Separator System (Isto Biologics, Hopkinton, MA). PRP was injected into the posterior vagina, vestibule, and posterior fourchette. The primary outcome was a change in patient-reported GSM symptoms using the validated Vulvovaginal Symptom Questionnaire (VSQ), compared at baseline (T0) and one month after the treatment #2 (T1). Secondary outcomes included vaginal health index (VHI) collected on exam, as well as patient-reported sexual function (Female Sexual Function Index: FSFI) and sexual distress (Female Sexual Distress Scale-Revised: FSDS-R). Lower VSQ and FSDS correspond to less GSM symptoms and lower sexual distress, respectively, whereas higher VHI and FSFI correspond to less atrophy and greater sexual function. Exploratory analyses included outcome assessment at 6 months (T2). Paired t-tests compared mean score differences between timepoints. Results: 18 breast cancer patients were enrolled (2023-2025), 17 received 2 treatments. Median age was 51.5 years (38-66), 89% received chemotherapy, and all patients were on endocrine therapy during the trial. Mean VSQ, FSDS-R, and VHI significantly improved from T0 to T1 (Table 1), and remained significantly improved at T2 (n=11). Of 7 sexually inactive patients at enrollment, 5 resumed sexual activity during the study. Post-treatment pain scores were low, and one patient developed post-treatment itching requiring an antihistamine and fluconazole. Conclusion: Two treatments of vulvovaginal PRP improved breast cancer patient-reported vulvar symptoms and lowered sexual distress when applied in a standard application, and the improvements appear to be durable for 6 months after completing treatment. Funding: SCCC Cancer Survivorship Research Pilot Award (CC-CSRP-2023) Citation Format: M. Curran, T. Wolde, J. Firdman Moore, G. Sierra, N. Paez, L. Pla, A. Van Mossel, K. Rojas. A phase II trial of platelet-rich plasma for breast cancer patients with genitourinary syndrome of menopause abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS5-04-25.
Curran et al. (Tue,) studied this question.