Table 4.

Adjusted odds ratios for young-onset breast cancer associated with menopause-associated symptoms, stratified by ER status

	ER+			ER-
Characteristics†	Control (n=1285)	Cases (n=1095)	OR (95% CI)‡	Control (n=350)	Cases (n=296)	OR (95% CI)‡	p for heterogeneity
	No. (%)	No. (%)		No. (%)	No. (%)
Had any menopause-associated symptoms prior to index age
No	929 (72.5)	908 (83.0)	1.00	263 (75.1)	230 (77.7)	1.00
Yes	353 (27.5)	186 (17.0)	0.44 (0.35, 0.57)	87 (24.9)	66 (22.3)	0.67 (0.42, 1.06)	0.07
Had hot flashes prior to index age
No	1005 (78.8)	974 (89.3)	1,00	278 (80.1)	242 (82.3)	1.00
Yes	271 (21.2)	117 (10.7)	0.40 (0.30, 0.54)	69 (19.9)	52 (17.7)	0.66 (0.40, 1.10)	0.07
Had other menopause-associated symptoms prior to index age
No	1001 (78.3)	934 (85.8)	1.00	282 (81.0)	240 (81.1)	1.00
Yes	278 (21.7)	154 (14.2)	0.49 (0.37, 0.63)	66 (19.0)	56 (18.9)	0.85 (0.53, 1.37)	0.04

Missing data: ER+: Hot flashes (n=13), other symptoms (n=13), any menopausal symptoms (n=4)

ER-: Hot flashes (n=5), other symptoms (n=2)

Other menopause symptoms: poor sleeping, night sweats, irritability, or depression, etc

^†Menopause symptoms were defined as ever prior to index age; menopause symptoms reported as first occurring after index age were not treated as relevant.

^‡Adjusted for birth order and menopausal status at index age (premenopausal, postmenopausal, premenopausal hysterectomy with retained ovary tissue)