Breast cancer is one of the most commonly diagnosed cancers globally and a leading cause of death among women. Surgical treatment is a fundamental and indispensable component of the breast cancer treatment regimen. Neoadjuvant chemotherapy is used in the treatment of breast cancer to reduce tumor size in locally advanced breast cancer, enabling breast-conserving surgery and reducing the need for axillary dissection. Following surgical treatment for breast cancer, patients often face issues related to upper extremity function. In addition to medical treatment post-surgery, a multidisciplinary approach is required that not only considers the patient's pathological conditions but also addresses psychological, social, and occupational rehabilitation, aiming to preserve and improve the patient's quality of life. Transcutaneous electrical nerve stimulation (TENS) is one of the non-pharmacological treatments associated with strong analgesic effects following mastectomy. As a non-invasive and easily applicable method, TENS therapy is expected to lead to a reduction in pain intensity and mobility restrictions, along with an increase in patient satisfaction and quality of life. Additionally, TENS provides patients with a voice in pain management, raises awareness among healthcare professionals regarding pain control, and contributes to pain management, thereby improving the quality of life of individuals. This study will evaluate the effect of TENS use on the prevention of lymphedema development after breast surgery, as well as include patient feedback, using a mixed-methods approach.

This study will be conducted with patients who have undergone breast surgery, employing both qualitative and quantitative research designs during the postoperative period. In the quantitative phase of the study, TENS will be applied to patients for one month after breast surgery, and measurements will be taken during the first three days of hospitalization. Later, during the first and third-month follow-up visits, pain intensity, lymphedema development, upper extremity function, and quality of life will be reassessed. In the qualitative phase, which will involve patients in the intervention group, individual in-depth interviews will be conducted using a semi-structured form to explore the patients' experiences with the TENS application during the first month, at their first postoperative control visit.