Vaginal Laser Therapy for Genitourinary Syndrome of Menopause in Breast Cancer Survivors: A Modality-Specific Systematic Review of Efficacy, Durability, and Safety.

Background

Genitourinary syndrome of menopause (GSM) is common among breast cancer survivors, particularly during endocrine therapy, and vaginal laser therapy has been proposed as a nonhormonal option; CO2 and Er:YAG devices differ technically and their effects should not be assumed equivalent.

Objective

To assess the efficacy, durability, and safety of vaginal laser therapy for GSM in breast cancer survivors, treating CO2 and Er:YAG separately.

Methods

Five databases and trial registries were searched from inception to 22 August 2026. Risk of bias was assessed with RoB 2, ROBINS-I, and the JBI cohort checklist; certainty with GRADE; and findings were synthesized narratively because of heterogeneity.

Results

Thirty-five evidence reports represented 28 study families (19 CO2, six Er:YAG alone, one Er:YAG plus Nd:YAG versus Er:YAG, two other systems). Only two CO2 trials used sham controls, and neither showed a reproducible laser-specific benefit for dyspareunia or overall sexual function; one favored CO2 for daily dryness and selected objective measures but not intercourse dryness or dyspareunia. Active-comparator trials showed no consistent laser advantage, and uncontrolled cohorts reported short-term gains that attenuated with follow-up. No serious treatment-related adverse event was reported in the included studies; however, the evidence was insufficient to assess uncommon or delayed harms. Certainty was low to very low for sham-controlled CO2 effects and very low for Er:YAG versus hyaluronic acid; no study compared the modalities directly.

Conclusions

Available evidence does not establish a consistent laser-specific benefit on the main patient-reported outcomes. CO2 has the larger evidence base, but this does not demonstrate greater efficacy; Er:YAG data rely mainly on active-comparator or uncontrolled studies. No direct CO2-versus-Er:YAG comparison is available, and neither modality superiority nor equivalence can be inferred. Durability and safety beyond the short term remain uncertain.