Surgical Impacts of Metastatic Non-small Cell Lung Cancer to the Thoracic and Lumbar Spine

Abstract

Background: Surgery for spinal metastasis is rapidly increasing in frequency with procedures ranging from laminectomy to spondylectomy combined with stabilization. This study investigated the effect of various surgical procedures for spinal metastasis of non-small cell lung cancer (NSCLC).

Methods: A single-center consecutive series of patients who underwent surgery for spinal metastasis of NSCLC were retrospectively reviewed. Patients' characteristics, radiographic parameters, operative data, clinical outcomes, and complications were analyzed. Surgical outcomes were assessed according to pain and performance status before and after surgery. Overall survival (OS) rate was estimated using the Kaplan-Meier method. Multivariate analysis was performed to detect factors independently associated with OS using a Cox proportional hazards model.

Results: Twenty-one patients were treated with laminectomy, 24 with corpectomy, 13 with spondylectomy (piecemeal or total en bloc fashion), and all procedures were combined with stabilization. Back pain and performance status improved significantly after surgical treatment among the three groups. Revision surgery due to tumor progression at the index level or spinal metastasis at another level were four patients (19.0%) in the laminectomy group, six patients (25.0%) in the corpectomy group, and one patient (7.7%) in the spondylectomy group. A Charlson comorbidity index and the number of spinal metastasis negatively affected OS (hazard ratio [HR], 19.613 and 2.244). Postoperative chemotherapy, time to metastasis, spondylectomy, and corpectomy had favorable associations with OS (HR, 0.455, 0.487, 0.619, and 0.715, respectively).

Conclusion: Postoperative chemotherapy was the most critical factor in OS of patients with metastatic NSCLC to the spine. An extensive surgical procedure (corpectomy/spondylectomy) with stabilization also could be beneficial for limited patients with spinal metastasis of NSCLC.

Keywords: Corpectomy; Laminectomy; Non-small Cell Lung Cancer; Overall Survival Rate; Spinal Metastasis; Spondylectomy.

Fig. 1. Schematic representation for describing the different possible techniques to remove spinal metastasis.

Fig. 2. Assessments of back pain in the laminectomy group, corpectomy group, and spondylectomy group preoperatively and at postoperative 3, 6, 9, and 12 months.

Fig. 3. Changes in functional status (ECOG performance) after surgery in the three groups. (A) In the laminectomy group, the ECOG improved or remained unchanged in 3/21 (14.3%) of the patients at 12 months postoperative. (B) In the corpectomy group, the ECOG improved or remained unchanged in 9/24 (37.5%) of the patients at 12 months postoperative. (C) In the spondylectomy group, the ECOG improved or remained unchanged in 3/13 (23.1%) of the patients at 12 months postoperative.

ECOG = Eastern Cooperative Oncology Group.

Fig. 4. Kaplan-Meier graph of postoperative survival status in the three groups. The difference in postoperative survival time in patients treated with laminectomy, corpectomy, and spondylectomy was statistically significant (P = 0.043).