Clinical Application of Vagus Nerve Stimulation Combined With Immunoregulatory T Cells in Alleviating Aromatase Inhibitor-Induced Pain

Brief Summary

The goal of this clinical trial is to learn whether transcutaneous auricular vagus nerve stimulation, also called taVNS, can help relieve aromatase inhibitor-related joint and muscle pain in adult women with hormone receptor-positive breast cancer. The main questions this study aims to answer are: 1. Does taVNS reduce pain caused by aromatase inhibitor treatment? 2. Does taVNS improve quality of life, mood symptoms, and the need for pain medicine? 3. What side effects or medical problems occur during treatment? Researchers will compare active taVNS with sham stimulation. Participants in both groups will receive mild electrical stimulation around the ear, but the sham stimulation will be applied to an area not expected to activate the vagus nerve. Participants will: 1. Be randomly assigned to active taVNS or sham stimulation 2. Receive one 30-minute treatment session every day for 28 days 3. Complete pain, mood, and quality-of-life questionnaires before treatment, after treatment, and during follow-up 4. Report pain medicine use and any side effects 5. Provide small blood samples to measure inflammatory markers, T-cell profiles, and tumor markers Participants will be followed for up to 6 months after treatment. For some participants who do not have enough pain relief after taVNS, an optional second-stage study may be offered. In this stage, participants may receive low-dose interleukin-2, also called IL-2, by injection every other day for 2 weeks.