Diagnostic extended usefulness of RMI: comparison of four risk of malignancy index in preoperative differentiation of borderline ovarian tumors and benign ovarian tumors

Table 3 The distribution of benign ovarian tumors and BOTs including subgroup of BOTs by age, menopausal status, ultrasound score, serum CA125, and tumor size

Variables	Benign (n = 379)	BOTs (n = 162)	P value	SBOT	P value	MBOT	P value
Age (years) Mean ± SD	37.73 ± 14.61	40.3 ± 15.12	0.065^b	39.88 ± 14.32	0.168^b	41.24 ± 16.92	0.12^b
Menopausal status			0.88^c		0.77^c		0.438^c
Premenopausal	297	126		90		36
Postmenopausal	82	36		23		13
Ultrasound score^a n, (%)			N/A^c		N/A^c		N/A^c
0	159(42)	12 (7.4)		9		3
1	187(49.3)	81 (50)		53		28
2–5	33 (8.7)	69(42.6)		51		18
CA 125 (U/mL) Mean ± SD	34.77 ± 6.16	192.15 ± 98.13	N/A^d	235.63 ± 322.28	N/A^d	91.8 ± 202.61	N/A^d
Tumor size (cm)			N/A^c		0.505^c		N/A^c
<7	198	58		55		3
≥7	181	104		58		46

^aUltrasound scores were recorded as one point for each of the following characteristics: multilocularity, solid areas, bilaterality, ascites and intra-abdominal metastases
^bStudent’s t-test
^cChi square test
^dMann–Whitney U test