Prognostic Factors and Treatment of Spinal Astrocytomas

A Multi-institutional Cohort Analysis

Yingjie Zou, MD; James Sun, BA; Yangying Zhou, BS; Harrison Xiao Bai, MD; Xiangyan Huang, MD; Ranjith Babu, MD; Alessandro Landi, MD; Kap Sum Foong, MD; Zishu Zhang, MD; John H. Woo, MD; Yongguang Tao, PhD; Xuejun Li, MD, PhD; Xiangqi Tang, MD, PhD; Bo Xiao, MD, PhD; Paul J. Zhang, MD; Li Yang, MD, PhD

Disclosures

Spine. 2018;43(10):E565-E573. 

In This Article

Results

Multi-institutional Cohort

Retrospective chart review yielded 94 patients (Table 1). The median age was 29 years (range: 1–73). Sixty-four (68.1%) were men and 30 (31.9%) were women. Of the 79 patients for whom initial presenting symptoms were available, 50 (63.3%) experienced weakness, 37 (46.8%) sensory changes, 37 (46.8%) pain, and 13 (16.5%) bowel or bladder incontinence. For 35 patients with information on symptom duration, the median length before presentation was 4 months (range: 1–24). Of the 90 patients who had information on WHO grade, there was an even distribution: 20 (22.2%) grade I, 22 (24.4%) grade II, 23 (25.6%) grade III, and 25 (27.8%) grade IV. The median preoperative McCormick score was: I: 17 (18.1%), II: 52 (55.3%), III: 23 (24.5%), IV: 2 (2.1%). Resection was performed in 71 patients: GTR: 21 (29.6%), STR: 50 (70.4%). Twenty-three patients (24.5%) underwent biopsy only. Fifty-four patients (58.1%) received RT and 53 patients (57.0%) received chemotherapy. -

The median follow-up time was 24 months (range: 2–249). Sixty-four patients (68.1%) had recurrence or progression. The median PFS was 18 months (95% confidence interval [CI]: 12–24). Fourteen patients (16.7%) had metastases. The median OS was 28 months (95% CI: 23–40). The median postoperative McCormick score was II: I - 13 (13.8%), II - 42 (44.7%), III - 34 (36.2%), IV - 3 (3.2%), V - 2 (2.1%). The paired difference in McCormick scores was found to be significant (P < 0.001): scores decreased by 1 in 2 cases (2.1%), showed no change in 69 cases (73.4%), increased by 1 in 22 cases (23.5%), and increased by 3 in 1 case (1.1%). Subgroup analysis of the change in McCormick score by extent of resection revealed no differences among groups (P = 0.551). Seventy-four (78.7%) patients deceased at the end of follow-up.

Results of the univariate analysis on both PFS and OS are shown in Table 2. On multivariate analysis for PFS, WHO grade IV (HR: 3.92, 95% CI: 1.27–12.08, P = 0.017) tumors had shorter PFS than those of lower grades (Table 3, Figure 1), whereas GTR trended toward longer PFS (HR: 0.41, 95% CI: 0.14–1.27, P = 0.124) when compared to STR (Table 3). On multivariate analysis for OS, age older than 18 years (HR: 2.69, 95% CI: 1.36–5.32, P = 0.004), paresthesia as a presenting symptom (HR: 2.43, 95% CI 1.26–4.67, P = 0.008), WHO grade III (HR: 2.61, 95% CI: 01.03–6.63, P = 0.043), and IV (HR: 3.53, 95% CI: 1.42–8.78, P = 0.007) were associated with shorter OS, whereas thoracic tumor location (HR: 0.43, 95% CI: 0.24–0.78, P = 0.006) when compared to cervical tumor location, biopsy (HR: 0.43, 95% CI: 0.20–0.91, P = 0.028) when compared to STR, and RT (HR: 0.42, 95% CI: 0.20–0.88, P = 0.022) were associated with significantly longer OS. GTR trended toward longer OS (HR: 0.47, 95% CI: 0.17–1.30, P = 0.143) (Table 4, Figure 2).

Figure 1.

Kaplan-Meier survivor function for progression-free survival in the multi-institutional cohort. Factors shown (tumor grade) are those determined to be significant in multivariate Cox proportional hazard regression analysis (Table 2). WHO indicates World Health Organization.

Figure 2.

Kaplan-Meier survivor function for overall survival in the multi-institutional cohort. Factors shown (Age, Paraesthesia, Tumor Grade, Tumor Location, Extent of Resection, and Radiotherapy) are those determined to be significant in multivariate Cox proportional hazard regression analysis (Table 2).

Literature Cohort

Overall, data were extracted for 339 individual patients from 72 studies in the literature (Supplementary Figure 1, http://links.lww.com/BRS/B316, Supplementary Table 1, http://links.lww.com/BRS/B316). There were significant differences in age (P = 0.046), sex (P = 0.024), paresthesia as a presenting symptom (P = 0.018), tumor grade (P = 0.035), and treatment morbidity (P < 0.001) between the multi-institutional cohort and the literature cohort (Table 1). The median follow-up time was 26 months (range: 1–480). One hundred fifty-one patients (62.7%) had recurrence or progression. The median PFS was 25 months (95% CI: 18–38). At the end of follow-up, 13.7% of the patients (46/337) had metastases. The median OS was 50 months (95% CI: 36–124). One hundred fifty-eight (47.2%) patients deceased at the end of follow-up.

Results of the univariate analysis are shown in Supplementary Table 3, http://links.lww.com/BRS/B316. On multivariate analysis, GTR (HR 0.43, 95% CI: 0.24–0.77, P = 0.005) was associated with longer PFS when compared with STR, whereas WHO grades III (HR 3.14, 95% CI: 1.38–7.18, P = 0.007) and IV (HR 4.50, 95% CI: 2.05–9.88, P < 0.001) were associated with shorter PFS (Supplementary Table 4, http://links.lww.com/BRS/B316). On multivariate analysis for OS, WHO grades II (HR: 17.7, 95% CI: 2.27–138.0, P = 0.006), III (HR: 14.0, 95% CI: 1.80–109.5, P = 0.012), and IV (HR: 22.4, 95% CI: 2.93–171.5, P = 0.003) and recurrence/progression (HR: 4.17, 95% CI: 2.20–7.91, P < 0.001) were associated with shorter survival (Supplementary Table 5, http://links.lww.com/BRS/B316).

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