Predictive value of seven preoperative prognostic scoring systems for spinal metastases

Abstract

Predicting prognosis is the key factor in selecting the proper treatment modality for patients with spinal metastases. Therefore, various assessment systems have been designed in order to provide a basis for deciding the course of treatment. Such systems have been proposed by Tokuhashi, Sioutos, Tomita, Van der Linden, and Bauer. The scores differ greatly in the kind of parameters assessed. The aim of this study was to evaluate the prognostic value of each score. Eight parameters were assessed for 69 patients (37 male, 32 female): location, general condition, number of extraspinal bone metastases, number of spinal metastases, visceral metastases, primary tumour, severity of spinal cord palsy, and pathological fracture. Scores according to Tokuhashi (original and revised), Sioutos, Tomita, Van der Linden, and Bauer were assessed as well as a modified Bauer score without scoring for pathologic fracture. Nineteen patients were still alive as of September 2006 with a minimum follow-up of 12 months. All other patients died after a mean period of 17 months after operation. The mean overall survival period was only 3 months for lung cancer, followed by prostate (7 months), kidney (23 months), breast (35 months), and multiple myeloma (51 months). At univariate survival analysis, primary tumour and visceral metastases were significant parameters, while Karnofsky score was only significant in the group including myeloma patients. In multivariate analysis of all seven parameters assessed, primary tumour and visceral metastases were the only significant parameters. Of all seven scoring systems, the original Bauer score and a Bauer score without scoring for pathologic fracture had the best association with survival (P < 0.001). The data of the present study emphasize that the original Bauer score and a modified Bauer score without scoring for pathologic fracture seem to be practicable and highly predictive preoperative scoring systems for patients with spinal metastases. However, decision for or against surgery should never be based alone on a prognostic score but should take symptoms like pain or neurological compromise into account.

Fig. 1

The proposed modified Bauer score excluding pathologic fracture as a prognostic factor

Fig. 2

Survival curves for primary tumour growth rate in 69 patients with spinal metastases, including ten multiple myeloma patients (modified after Tomita et al. [16]: slow growth breast, thyroid, multiple myeloma, etc., moderate growth kidney, uterus, etc., fast growth lung, melanoma, liver, colon, etc.)

Fig. 3

Survival curves for the prognostic groups according to seven different scores, a–e, f, h 59 patients excluding multiple myeloma, g, i 69 patients including multiple myeloma: a Tokuhasi [15], b Tokuhashi revised [14], c Tomita [16], d Van der Linden [20], e Sioutos [13], f, g Bauer [2], h, i Bauer modified