This randomized, single-blind clinical trial will compare the effectiveness of multimodal pelvic floor physiotherapy (PPT) and fractional CO2 vaginal laser therapy in reducing genitourinary syndrome of menopause (GSM) symptoms among breast cancer (BC) survivors. GSM, induced by cancer treatments, is common in BC survivors due to hormonal deprivation, and effective non-hormonal treatments are needed. The study will enroll 210 women diagnosed with GSM following BC treatment, who will be randomly assigned to either three sessions of CO2 vaginal laser therapy or eight sessions of multimodal PPT, which includes pelvic floor muscle training, vaginal non-ablative radiofrequency, education, and moisturizers. Primary outcomes will include perineal pain, sexual function, and health-related quality of life (HRQoL), with assessments at baseline, post-intervention, and at 3, 6, and 12 months. The hypothesis is that multimodal PPT will lead to greater improvements in pelvic pain, muscle function, and sexual health, with sustained benefits over time. This trial aims to provide evidence for non-invasive, non-hormonal treatments to manage GSM in BC survivors, filling a significant therapeutic gap.

Background: Genitourinary syndrome of menopause (GSM) induced by breast cancer (BC) treatments is highly prevalent among BC survivors due to the abrupt hor-monal deprivation caused by oncological therapies. Given the contraindication of hor-monal treatments in this population, there is a critical need for effective non-hormonal alternatives to alleviate GSM symptoms.

Objectives: This study aims to compare the effectiveness of multimodal pelvic floor physiotherapy (PPT)-comprising pelvic floor muscle training, vaginal non-ablative radiofrequency, pelvic health education, and vaginal moisturizers-against fractional CO2 vaginal laser therapy in reducing GSM symptoms among BC survivors.

Methods: A randomized, single-blind clinical trial will be conducted with 210 women diagnosed with GSM after undergoing BC treatment. Participants will be ran-domly assigned (1:1) to receive either three sessions of CO2 vaginal laser therapy or eight face-to-face sessions of multimodal PPT. Assessments will be performed at base-line, immediately after the intervention, and at 3-, 6-, and 12- months post-intervention. Primary outcomes will include perineal pain, sexual function, and health-related quality of life (HRQoL). Additionally, a cost-effectiveness analysis will be conducted to evaluate the costs of each intervention relative to the changes in clinical outcomes, and any ad-verse effects will be monitored throughout the study.

Results: It is hypothesized that women undergoing multimodal PPT will show greater reductions in pelvic pain and improvements in pelvic floor muscle strength, endurance, and relaxation compared to those receiving CO2 laser therapy, alongside enhanced sexual function and HRQoL. These improvements are expected to be sus-tained in the short and medium term through continued adherence to home exercises and educational strategies.

Conclusions: This study aims to provide evidence for novel, non-invasive, and non-hormonal treatment strategies to manage GSM in BC survivors, addressing an important gap in the therapeutic landscape for this population.

Inclusion Criteria:

• Breast cancer survivors diagnosed with GSM as a result of cancer treatment
• Vaginal Health Index (VHI) score of ≤ 15.

Exclusion Criteria:

• History of conservative treatment or surgery for pelvic floor dysfunction or GSM
• Currently undergoing chemotherapy, or have undergone BC surgery but have not received chemotherapy or hormonal treatment.
• Presence of concomitant or systemic diseases that could interfere with the proposed treatments, such as a recurrence of the oncological process, active or recurrent untreated urinary tract infections, hematuria, or cognitive impairments that hinder the participant's ability to comprehend study information, respond to questionnaires, provide informed consent, or fully participate in the study.