(573) Mid-Term Objective Results of a Randomized Clinical Trial: Fractional Carbon Dioxide vs Sham Laser for Genitourinary Syndrome of Menopause on Breast Cancer Survivors Using Aromatase Inhibitors

Introduction Breast cancer (BC) patients frequently present more severe genitourinary syndrome of menopause (GSM). Last decades energy-based devices, e.g. vaginal laser therapy, emerged for GSM treatment to improve both vaginal and sexual symptoms. However, controversy is still behind this therapy due to most of publications without sham group, short-term follow-up, as well as heterogeneity comparing subjective versus objective efficacy results. Objective To assess the mid-term objective efficacy of CO2 vaginal laser in BC survivors receiving aromatase inhibitors suffering genitourinary syndrome of menopause. Methods Prospective double-blind sham controlled randomized controlled trial (RCT) with two parallel study arms: 1) CO2 vaginal laser therapy (CLT) and 2) Sham laser therapy (SLT), both underwent 5 monthly laser sessions (1). Herein, we present mid-term (1 year after inclusion) objective variables regarding efficacy, comparing before and after the intervention globally and by groups. Objective outcomes were based on vaginal pH and vaginal biopsy which included vaginal maturation index, vaginal epithelial thickness (measured in millimeters) and vaginal epithelial elasticity (measured in Pascals). This study followed the Consolidated Standards of Reporting Trials reporting guideline for RCTs. Results Among 84 randomized women (42 each arm), 67 participants were analyzed at 1-year follow-up (32 CLT vs 35 SLT). Of note, two out of three participants denied vaginal biopsy at that timepoint, despite their consent on baseline and short-term follow-up (6 months). A global analysis of all patients (n=58 for vaginal pH and n=26 for vaginal biopsy) has been performed comparing objective outcomes before and 1 year after inclusion (6 months after treatment) not separating by Laser groups, observing clear improvement in Vaginal pH (p=0.0003), Vaginal Maturation Index (p<0.001), Vaginal epithelial thickness (p<0.003) and Vaginal epithelial elasticity (p<0.001), without serum estradiol changes (p=0.197). On the other hand, when comparing the mean improvement between CLT vs SLT group, no differences were observed. Around 2 out of 5 participants during a 5 session treatment presented mild adverse events (spotting or vaginal itching) and 1 out of 8 moderate complications (urinary tract infection). No differences between CLT compared to SLT were observed regarding complications (p=0.67). Conclusions Significant improvements with respect to objective genital outcomes at 1-year follow-up, regardless of whether or not they received laser therapy, suggesting that vaginal laser treatment was not effective. Similarly to previously published short-term results (1), as well as, to previously preliminary results on mid-term subjective variables (ESSM abstract 2025). In line with the more robust evidence focused on high quality studies (2), which concludes that the effect of vulvar and vaginal laser decreases when potential biases have been eliminated. Disclosure Yes, this is sponsored by industry/sponsor: The Fractional microablative carbon dioxide laser system was provided by DEKA. The vaginal ovule moisturizer was provided by IntherPharma. External vaginal moisturizer and intimate lubricant were provided by the CumLaude Lab. Vaginal vibratorswere provided by BCNatal. No other funding sourceswere used. Clarification: Industry funding only - investigator initiated and executed study.