Metastatic spinal cord compression in non-small cell lung cancer patients: Prognostic factors in a series of 356 patients

Background: Patients with metastatic spinal cord compression (MSCC) from non-small cell lung cancer (NSCLC) have an unfavorable prognosis compared to most other MSCC patients. This study was performed to identify prognostic factors for functional outcome and survival in these patients after radiotherapy (RT) alone. Patients and methods: Data of 356 patients irradiated for MSCC from NSCLC were retrospectively analyzed. Ten potential prognostic factors were investigated including age, gender, Eastern cooperative Oncology Group performance score (ECOG-PS), number of involved vertebrae, pre-RT ambulatory status, other bone metastases, visceral metastases, interval from cancer diagnosis to RT of MSCC, time developing motor deficits before RT, and the radiation schedule. Results: On multivariate analysis, better functional outcome was associated with pre-RT ambulatory status (estimate:-0.84, p=0.022), no visceral metastases (estimate:-1.15, p<0.001), interval from cancer diagnosis to RT of >15 months (estimate: +0.48, p=0.019), and slower (>7 days) development of motor deficits (estimate: +1.56, p<0.001). On multivariate analysis, improved survival was significantly associated with female gender (risk ratio (RR) 1.32, p=0.043), ECOG-PS 1-2 (RR 1.45, p=0.034), pre-RT ambulatory status (RR 0.58, p<0.001), no other bone metastases (RR 1.38, p=0.010), no visceral metastases (RR 2.87, p<0.001), interval from cancer diagnosis to RT of >15 months (RR 0.84, p=0.035), and slower (>7 days) development of motor deficits (RR 0.78, p<0.001). Conclusion: This study identified additional independent prognostic factors for outcomes after radiotherapy of MSCC from NSCLC. These prognostic factors can be used for stratification in future trials and can help develop prognostic scores for MSCC from NSCLC.