Clinicopathological and Prognostic Characteristics in Spinal Chondroblastomas: A Pooled Analysis of Individual Patient Data From a Single Institute and 27 Studies

Abstract

Study design: Retrospective pooled analysis of individual patient data.

Objectives: Spinal chondroblastoma (CB) is a very rare pathology and its clinicopathological and prognostic features remain unclear. Here, we sought to characterize the clinicopathological data of a large spinal CB cohort and determine factors affecting the local recurrence-free survival (LRFS) and overall survival (OS) of patients.

Methods: Electronic searches using Medline, Embase, Google Scholar and Wanfang databases were performed to identify eligible studies per predefined criteria. A retrospective review was also conducted to include additional patients at our center.

Results: Twenty-seven studies from the literature and 8 patients from our local institute were identified, yielding a total of 61 patients for analysis. Overall, there were no differences in clinicopathological characteristics between the local and literature cohorts, except for absence or presence of spinal canal invasion by tumor on imagings and chicken-wire calcification in tumor tissues. Univariate Kaplan-Meier analysis revealed that previous treatment, preoperative or postoperative neurological deficits, type of tumor resection, secondary aneurysmal bone cyst (ABC), chicken-wire calcification and radiotherapy correlated closely with LRFS, though only type of tumor resection, chicken-wire calcification and radiotherapy were predictive of outcome based on multivariate Cox analysis. Analyzing OS, we found that a history of preoperative treatment, concurrent ABC, chicken-wire calcification, type of tumor resection and adjuvant radiotherapy had a significant association with survival, whereas only type of tumor resection remained statistically significant after adjusting for other covariables.

Conclusion: These data may be helpful in prognostic risk stratification and individualized therapy decision making for patients.

Keywords: chondroblastoma; clinical features; prognostic factors; spine; survival analysis.

Figure 1.

Flow diagram of literature search showing studies identified, included and excluded at each stage.

Figure 2.

Cut-off determination by using maximally selected rank statistics for duration of symptoms (Left) and patient age (Right) in survival analysis, with the overall survival as the outcome parameter. Patients were divided into high-risk and low-risk groups according to the cut-off values.

Figure 3.

Kaplan-Meier curves of local recurrence-free survival of spinal chondroblastoma patients, stratified by history of previous treatment (P = 0.011 via log-rank test), type of surgical resection (P = 0.027), neurological deficits before surgery (P = 0.034), neurological deficits after surgery (P = 0.001), secondary aneurysmal bone cyst (P = 0.033), adjuvant radiotherapy (P = 0.001) and chicken-wire calcification (P = 0.001).

Figure 4.

Kaplan-Meier curves of overall survival of spinal chondroblastoma patients, stratified by history of previous treatment (P < 0.001 via log-rank test), type of surgical resection (P = 0.038), secondary aneurysmal bone cyst (P = 0.005), adjuvant radiotherapy (P < 0.001) and chicken-wire calcification (P < 0.001).

Figure 5.

Multivariate Cox regression model for local recurrence-free survival of patients with spinal chondroblastoma.

Figure 6.

Multivariate Cox regression model for overall survival of patients With spinal chondroblastoma.