Table 2.

Univariate analysis of prognostic factors for Recurrence-free survival rates of spinal chordoma patients

Factors	Categories	χ 2	P-value
Sex	Male/Female	0.033	0.857
Age	≤ 50/> 50	1.536	0.215
Tumor size	≤ 5 cm/> 5 cm	0.044	0.834
Tumor location	Sacral vertebra/Cervical or thoracic vertebra	0.611	0.434
Preoperative recurrence	Yes/No	0.000	0.984
Surrounding muscle invasion	Yes/No	26.917	0.000*
miR-140-3p expression	High/Low	31.270	0.000*

^* P < 0.05.