Columnar cell lesions and subsequent breast cancer risk: a nested case-control study

Breast Cancer Research

Table 1 Characteristics by CCL status among controls with BBD*

	CCL	No CCL
No. of controls (%)	448 (27.9)	1,158 (72.1)
Means
Age at BBD biopsy, years	45.1	43.3
Year of BBD biopsy (median)	1979	1979
Time since BBD biopsy, years	9.3	10.1
No. of BBD biopsy slides†	5.7	5.5
Body mass index, kg/m²†	24.2	25.0
Body mass index at age 18, kg/m²†	20.5	21.1
Weight gain after age 18, kg†	10.0	10.7
Age at menarche, years†	12.7	12.6
Age at first birth, years (parous only)†	24.9	24.9
Alcohol intake, g/day†	4.2	4.0
Parity (parous only)†	3.0	3.0
Percentages
Premenopausal†	36.0	35.5
Parous†	91.9	92.4
First degree family history of breast cancer†	19.0	17.6
Ever postmenopausal hormone use†	32.0	37.3
Ever oral contraceptive use†	45.1	49.6
Histologic category of BBD†
Nonproliferative	21.5	44.4
Proliferative without atypia	61.8	48.4
Atypical hyperplasia	16.8	7.2

CCL indicates columnar cell lesions; BBD, benign breast disease.
*Unless otherwise specified, all variables correspond to the time period immediately prior to the index date.
†Means and percentages were standardized to the age distribution of the controls at the time of benign biopsy, in five-year categories.

ISSN: 1465-542X