Survival in patients with surgically treated spinal metastases

Despite the various treatment protocols available, survival evaluation is a fundamental criterion for the definition of surgical management; there are still many inconsistencies in the literature on this topic, especially in terms of the value of surgery and its morbidity in patients with very short survival.

The objective was to analyze the association of clinical, oncological, and surgical factors in the survival of patients undergoing spinal surgery for spinal metastases (SM).

A retrospective cohort of forty patients who were surgically treated at our institution for SM between 2010 and 2018 were included in the study. We applied the prognostic scales of Tomita and Tokuhashi in each patient and evaluated the systemic status using Karnofsky Performance Scale (KPS) and Eastern Cooperative Oncology Group Performance Scale. Survival rate in months was estimated using the Kaplan-Meier curve, with death considered as primary outcome and, for the evaluation of the association between the variables, the Chi-square test, Fisher's exact test, or Fisher-Freeman-Halton test was applied for better survival. The level of statistical significance was considered as 5% (P ≤ 0.05).

The mean survival was 8.4 months. Patients with KPS <70 had a mean survival of 6.36 months, while those with KPS >70 had a mean survival of 14.48 months (P = 0.04). The mean survival of patients classified as ECOG 2 was 7.05 months (95% confidence interval [CI]: 3.4-10.7), and that of patients classified as ECOG 3 and 4 was 1.24 months (95% CI: 0.8-1.59). The mean survival rate among the patients with unresectable metastases in other organs was 6.3 months (95% CI: 3.9-8.9), while the survival rate of those who did not have metastases was 13.8 months (95% CI: 10.0-17.68; P = 0.022).

Survival was associated with the preoperative functional status defined by the KPS and ECOG scales and with the presence of nonresectable visceral metastases.