Table 1.

Baseline data comparison

Number	group	case	age	BMI	marriage	history of gestation
1	p16+/ki67+	509	45.13±6.54	22.01±3.57
2	P16+/ki67-	601	44.33±8.91	21.89±4.22
3	P16-/ki67+	403	40.87±9.67	22.63±5.16
4	P16-/ki67-	387	42.34±8.66	22.11±9.11
	Statistical index		T=0.648	T=0.846	X2=7.640	X2=10.342
			P=0.463	P=0.399	P=0.131	P=0.954

Note: Age, body mass index, marital status, and maternal history all showed no statistical significance in four groups of patients.