Outcomes after radiotherapy alone for metastatic spinal cord compression in patients with oligo-metastatic breast cancer

Background/Aim: Patients with oligo-metastatic breast cancer are a unique patient subgroup with more favourable outlook than most patients with metastatic disease. Prognostic factors in these patients with metastatic spinal cord compression (MSCC) were evaluated. Patients and Methods: In 159 patients irradiated for MSCC from oligo-metastatic breast cancer, seven characteristics were retrospectively analyzed including age, interval between breast cancer diagnosis and irradiation of MSCC, time developing motor deficits, ambulatory status, involved vertebrae, performance score (ECOG-PS) and radiotherapy regimen. Results: Improvement of motor function was significantly associated with time developing motor deficits (p=0.017), post-radiotherapy ambulatory status with pre-radiotherapy ambulation (p=0.012) and ECOG-PS 1-2 (p=0.029). Radiation doses of 39-40 Gy (equivalent doses) resulted in 1- and 2-year local control of 100% and 95%. On multivariate analyses, higher doses were associated with local control (p=0.011). Pre-radiotherapy ambulatory status (p=0.001) and ECOG-PS 1-2 (p=0.002) were associated with survival. Conclusion: Significant prognostic factors were identified for patients with MSCC from oligo-metastatic breast cancer. Higher radiation doses improved local control.