Table 2 Univariate Cox proportional hazards regression analysis for the overall survival and relapse-free survival of osteosarcoma patients

Age, years, ≥ 30 (vs. <30)

13/37

2.398 (0.938–6.134)

0.068

2.925 (1.210–7.070)

0.017

Sex, male (vs. female)

25/37

1.140 (0.402–3.229)

0.806

1.513 (0.541–4.228)

0.430

Tumor size, > 8 cm (vs. ≤ 8 cm)

18/37

3.975 (1.401–11.280)

0.010

3.067 (1.204–7.813)

0.019

Stage, ≥ II (vs.. I)

26/37

4.829 (1.107–21.058)

0.036

3.267 (0.953–11.206)

0.060

Histologic grade, 3 & 4 (vs. 1 & 2)

27/37

4.502 (1.031–19.666)

0.045

5.130 (1.184–22.222)

0.029

Lymph node metastasis, presence (vs.. absence)

3/37

5.373 (1.026–28.150)

0.047

2.981 (0.628–14.142)

0.169

Distant metastasis, presence (vs. absence)

7/37

5.347 (1.793–15.950)

0.003

3.802 (1.295–11.163)

0.015

SIRT6, positive (vs. negative)

18/37

4.012 (1.419–11.344)

0.009

4.151 (1.570-10.971)

0.004