Table 1.

Characteristics of endometrial cancer patients and non-endometrial cancer controls by oophorectomy status

	Total		Premenopausal bilateral oophorectomy		Postmenopausal bilateral oophorectomy
	Non-EC	EC	Non-EC	EC	Non-EC	EC
Number	281	412	169	181	112	231
	Ovarian tumor: 146		Ovarian tumor: 68		Ovarian tumor: 78
	Cervical cancer: 69		Cervical cancer: 53		Cervical cancer: 16
	Myoma or endometriosis: 51		Myoma or endometriosis: 43		Myoma or endometriosis: 8
	Others: 15		Others: 5		Others: 10
Age, years
Average	54.1	59.9	48.1	51.6	62.4	66.3
P (F test)	0.89		0.68		0.92
Interval from surgical menopause
Average			5.2	7.0	NA
P (F test)			0.86
Interval from natural menopause
Average			NA		11.6	15.1
P (F test)					0.27
Body mass index, kg/m2
Average	21.3	23.2	21.2	23.7	21.4	22.8
P (Mann–Whitney U test)	8.3 × 10−11		3.6 × 10−8		3.9 × 10−5

BMI, body mass index; EC, endometrial cancer; non-EC, non-endometrial cancer; NA, not applicable.