Table 3.

Menopausal symptoms and risk of breast cancer by histologic type

	Controls (n=449)	Ductal cases (n=494)		Lobular cases (n=307)		Ductal-lobular cases (n=187)
	n (%)	n (%)	OR‡ (95%CI)	n (%)	OR‡ (95%CI)	n (%)	OR‡ (95%CI)
Never had menopausal symptoms	51 (11.4)	96 (19.4)	1.0 (ref)	56 (18.2)	1.0 (ref)	25 (13.4)	1.0 (ref)
Ever had menopausal symptoms	398 (88.6)	398 (80.6)	0.5 (0.3–0.7)†	251 (81.8)	0.5 (0.3–0.8)^	162 (86.6)	0.7 (0.4–1.2)
Number of menopausal symptoms experienced
1	59 (13.1)	72 (14.6)	0.6 (0.4–1.0)	52 (16.9)	0.7 (0.4–1.3)	32 (17.1)	1.1 (0.5–2.2)
2	114 (25.4)	119 (24.1)	0.5 (0.3–0.7)†	69 (22.5)	0.4 (0.3–0.7)†	49 (26.2)	0.7 (0.4–1.3)
≥3	225 (50.1)	207 (41.9)	0.4 (0.3–0.7)†	130 (42.4)	0.4 (0.3–0.7)†	81 (43.3)	0.6 (0.3–1.0)
P for trend			0.126		0.049		0.028
Ever had severe menopausal* symptoms	180 (100)	166 (100)	0.5(0.3–0.7)†	115 (100)	0.5(0.3–0.8)†	71 (100)	0.8(0.4–1.5)
Number of severe menopausal symptoms among women who ever experienced a menopausal symptom
Never had menopausal symptoms	51	96	1.0 (ref)	56	1.0 (ref)	25	1.0 (ref)
1	83 (46.1)	81 (48.8)	0.5 (0.3–0.8)†	52 (45.2)	0.5 (0.3–0.9)†	42 (59.1)	0.9 (0.5–1.7)
2	55 (30.6)	48 (28.9)	0.4 (0.2–0.7)†	30 (26.1)	0.4 (0.2–0.8)†	19 (26.8)	0.6 (0.3–1.3)
≥3	42 (23.3)	37 (22.3)	0.4 (0.2–0.8)†	33 (28.7)	0.6 (0.3–1.1)	10 (14.1)	0.4 (0.2–0.9)†
P for trend			0.296		0.877		0.070
Ever had vasomotor symptoms	355 (89.2)	355 (89.2)	0.5 (0.3–0.7)†	225 (89.6)	0.5 (0.3–0.8)†	141 (87.0)	0.7 (0.4–1.2)
Ever had urogenital atrophy symptoms	257 (64.6)	244 (61.3)	0.4 (0.3–0.7)†	148 (59.0)	0.5 (0.3–0.7)†	100 (61.7)	0.7 (0.4–1.2)
Ever had emotional changes or insomnia	170 (42.7)	175 (44.0)	0.5 (0.3–0.8)†	108 (43.0)	0.5 (0.3–0.8)†	71 (43.8)	0.8 (0.4–1.4)

^*Thirty women (13 controls, 12 IDC cases, and 5 ILC cases) had missing data on intensity of menopausal symptoms and excluded from the analysis.

^†p-value <0.05.

^‡All odds ratios (OR) are adjusted for age, year, duration of hormone therapy use, and the type of menopause.