Table 2 Univariate Cox regression analysis for evaluating the influence of Regional dissection on survival of patients with primary metastatic osteosarcoma in SEER database

Treatment

 Non-regional dissection

Reference

Reference

 Regional dissection

0.34 (0.26-0.44)

<0.001

0.33 (0.25-0.43)

<0.001

Sex

 Female

Reference

Reference

 Male

1.00 (0.78-1.29)

0.980

1.03 (0.79-1.33)

0.851

Race

 White

Reference

Reference

 Black

0.77 (0.53-1.12)

0.170

0.72 (0.48-1.08)

0.114

 Other race

1.29 (0.82-2.02)

0.268

1.39 (0.89-2.18)

0.152

Age

 <18

Reference

Reference

 18-65

2.16 (1.66-2.80)

<0.001

2.14 (1.63-2.81)

<0.001

 >=65

4.11 (2.65-6.38)

<0.001

4.48 (2.88-6.98)

<0.001

Grade

 Well/moderate

Reference

Reference

 Poorly/undifferentiated

0.53 (0.28-1.00)

0.049

0.48 (0.25-0.91)

0.024

 Unknown

0.65 (0.34-1.27)

0.212

0.61 (0.31-1.19)

0.148

T Stage

 T1

Reference

Reference

 T2

0.97 (0.68-1.39)

0.884

0.97 (0.67-1.39)

0.855

 T3

1.48 (0.84-2.59)

0.171

1.56 (0.88-2.75)

0.121

 Tx

1.26 (0.84-1.88)

0.269

1.13 (0.74-1.72)

0.584

Chemotherapy

 No/unknown

Reference

Reference

 Yes

0.53 (0.34-0.83)

0.005

0.49 (0.31-0.76)

0.001

Radiation

 No/unknown

Reference

Reference

 Yes

2.20 (1.62-2.99)

<0.001

2.20 (1.60-3.03)

<0.001

Location

 Extremity

Reference

Reference

 Other

2.53 (1.89-3.41)

<0.001

2.50 (1.84-3.41)

<0.001