Breast-feeding and benign breast disease

Figures & data

Table I. Population characteristics.

Age (years)*	31.5 ± 6.1
Age at menarche (years)*	13.0 ± 1.5
Gynaecological age (years)*	18.4 ± 6.4
Weight (kg)*	59.0 ± 10.0
Height (cm)*	166.6 ± 6.3
BMI (kg/m²)*	21.2 ± 3.4
Cumulative lactation (years)^†	12 (4–20)
Lactation per child (years)^†	9 (3–13)
Age at 1st pregnancy (years)*	26.5 ± 5.4
Contraceptive use^‡	60% (63/105)
Contraception time (years)*	5.7 ± 5.0
Parity*	0.6 ± 0.9
Nulliparity^‡	58% (61/105)
Maximal lesion size (mm)*	22.8 ± 12.28
Breast size*	2.8 ± 1.0
Mastalgia^‡	47% (49/105)
Pruritus^‡	1% (1/105)
Nipple discharge^‡	6% (6/105)
Previous breast surgery^‡	39% (41/105)

Data are presented as: *mean ± SD, ^†median (IQR), ^‡prevalence.

Table II. BBDs prevalence in the general population, in nullipara and in pluripara women.

	General population (n = 105)		Nullipara (n = 68)		Pluripara (n = 37)
	n	(%)	n	(%)	n	(%)	p value
Fibroadenoma	58	55	40	59	18	49	NS
Fibrocystic changes	20	19	13	19	7	19	NS
Inflammatory breast disorders	5	5	2	3	3	8	< 0.05

Data are presented as percentage and significance is calculated between nullipara and pluripara with χ²-test or Fisher's exact test.

Figure 1. Comparison of breast-feeding duration among BBDs and controls (median, interquartile range and Kruskal–Wallis test).

Table III. Comparison of nullipara with pregnant women who cumulatively breast-fed more or less than 20 months, and who breast-fed more or less than 13 months/child.

		Breast-feeding
	Nullipara	< 20 months	> 20 months	p value	< 13 months	> 13 months	p value
Age (years)*	29.5 ± 6.2	35.1 ± 3.8	36.1 ± 4.3	< 0.05	35.7 ± 3.0	34 ± 6.53	< 0.05
Gynaecological age (years)*	16.1 ± 6.4	22.3 ± 4.1	23.2 ± 4.1	< 0.05	22.8 ± 3.5	21.1 ± 6.07	< 0.05
BMI (kg/m²)*	20.8 ± 2.7	22.1 ± 4.7	21.0 ± 1.9	0.279	22.1 ± 4.5	20.7 ± 1.9	0.248
Breast size*	2.6 ± 0.8	3.1 ± 1.4	2.5 ± 0.4	0.230	2.9 ± 1.3	4.0 ± 1.4	0.139
Fibroadenoma^†	59% (40/68)	46% (13/28)	56% (5/9)	0.540	53% (16/30)	29% (2/7)	0.300
Fibrocystic changes^†	19% (13/68)	21% (6/28)	11% (1/9)	0.790	20% (6/30)	14% (1/7)	0.941
Inflammatory breast disorders^†	3% (2/68)	3.6% (1/28)	22% (2/9)	< 0.05	3% (1/30)	29% (2/7)	< 0.05
Lesion number (> 2)^†,‡	15% (6/40)	0% (0/13)	80% (4/5)	< 0.05	13% (2/16)	100% (2/2)	< 0.05

Data are presented as: *mean ± SD and as ^†prevalences (with absolute values). Significance is calculated with χ²-test or one-way ANOVA. ^‡Only fibroadenomas.

Table IV. Correlation between ≥ 2 locations of fibroadenoma and breast-feeding duration by mono- and multivariate logistic regression.

	Monovariate regression			Multivariate regression
	OR	95% CI	p value	OR	95% CI*	p value
Months of lactation	1.05	1.00–1.08	< 0.05	1.01	0.99–1.09	0.056
Months of lactation/child	1.07	1.01–1.16	< 0.05	1.06	1.00–1.17	< 0.05

Data are presented as odds ratio (OR) and 95% confidence interval (95% CI). *In the multivariate model, we corrected for: age, parity, BMI, hormonal contraception usage and menarche.