Evaluation of Body Posture After Unilateral Mastectomy in Breast Cancer Patients: A Retrospective Single-Center Study

Objective: This study aimed to quantify the pre- and postoperative changes in spinal alignment in patients treated with unilateral mastectomy for breast cancer using the Cobb angle, and to evaluate the long-term postural effects of surgery.Materials and Methods: This retrospective, single-center study included 29 patients who underwent unilateral simple mastectomy or modified radical mastectomy for histopathologically confirmed breast cancer between January 2, 2020, and September 30, 2024, with a minimum postoperative follow-up of 12 months. Cobb angles were measured from coronal vertebral sections on positron emission tomography-computed tomography scans obtained before and after surgery. Vertebral curvature direction and slope side (ipsilateral, contralateral, or neutral relative to the mastectomy side) were determined. The magnitude of postural change was calculated as the absolute difference between postoperative and preoperative Cobb angles.Results: The mean age was 53.55 ± 13.32 years, and the mean BMI was 29.33 ± 5.84 kg/m². The mean preoperative Cobb angle was 7.16 ± 7.05°, increasing to 9.03 ± 6.23° postoperatively (z = 3.353, p = 0.001). Contralateral postural tilt developed in 62.1% of patients. Ten patients (34.5%) exceeded the ≥10° scoliosis threshold postoperatively, compared with seven (24.1%) preoperatively. BMI differed significantly according to slope side (p = 0.016).Conclusion: Measurable postural changes in spinal alignment develop following unilateral mastectomy, predominantly in the contralateral direction. These findings suggest that postural assessment should be integrated into long-term postoperative follow-up, and early rehabilitation strategies should be considered when indicated.