TY - JOUR
T1 - Cigarette smoking and mammographic density in the Danish Diet, Cancer and Health cohort
AU - Jacobsen, Katja Kemp
AU - Lynge, Elsebeth
AU - Vejborg, Ilse
AU - Tjønneland, Anne
AU - von Euler-Chelpin, My
AU - J. Andersen, Zorana
N1 - Publisher Copyright:
© 2015, Springer International Publishing Switzerland.
PY - 2016/2/1
Y1 - 2016/2/1
N2 - Purpose: Smoking before first childbirth increases breast cancer risk, but the biological mechanism remains unknown and may involve mammographic density (MD), one of the strongest biomarkers of breast cancer risk. We aimed to examine whether active smoking and passive smoking were associated with MD. Methods: For the 5,356 women (4,489 postmenopausal) from the Danish Diet, Cancer and Health cohort (1993–1997) who attended mammographic screening in Copenhagen (1993–2001), we used MD (mixed/dense or fatty) assessed at the first screening after cohort entry. Active smoking (status, duration, and intensity) and passive smoking were assessed at cohort baseline (1993–1997) via questionnaire, together with other breast cancer risk factors. Logistic regression was used to estimate associations (odds ratios, 95 % confidence intervals) between smoking and MD, adjusting for confounders. Results: Two thousand and twenty-six (56.5 %) women had mixed/dense MD, 2,214 (41.4 %) were current, and 1,175 (21.9 %) former smokers. Current smokers had significantly lower odds (0.86, 0.75–0.99) of having mixed/dense MD compared to never smokers, while former smoking was not associated with MD. Inverse association between smoking and MD was strongest in women who initiated smoking before age of 16 years (0.79, 0.64–0.96), smoked ≥15 cigarettes/day (0.83, 0.71–0.98), smoked ≥5 pack-years (0.62, 0.43–0.89), smoked >30 years (0.86, 0.75–0.99), and smoked ≥11 years before first childbirth (0.70, 0.51–0.96). Association between smoking and MD diminished after smoking cessation, with increased odds of having mixed/dense breasts in women who quit smoking >20 years ago as compared to current smokers (1.37, 1.01–1.67). There was no association between passive smoking and MD. Conclusions: We found an inverse association between active smoking and MD.
AB - Purpose: Smoking before first childbirth increases breast cancer risk, but the biological mechanism remains unknown and may involve mammographic density (MD), one of the strongest biomarkers of breast cancer risk. We aimed to examine whether active smoking and passive smoking were associated with MD. Methods: For the 5,356 women (4,489 postmenopausal) from the Danish Diet, Cancer and Health cohort (1993–1997) who attended mammographic screening in Copenhagen (1993–2001), we used MD (mixed/dense or fatty) assessed at the first screening after cohort entry. Active smoking (status, duration, and intensity) and passive smoking were assessed at cohort baseline (1993–1997) via questionnaire, together with other breast cancer risk factors. Logistic regression was used to estimate associations (odds ratios, 95 % confidence intervals) between smoking and MD, adjusting for confounders. Results: Two thousand and twenty-six (56.5 %) women had mixed/dense MD, 2,214 (41.4 %) were current, and 1,175 (21.9 %) former smokers. Current smokers had significantly lower odds (0.86, 0.75–0.99) of having mixed/dense MD compared to never smokers, while former smoking was not associated with MD. Inverse association between smoking and MD was strongest in women who initiated smoking before age of 16 years (0.79, 0.64–0.96), smoked ≥15 cigarettes/day (0.83, 0.71–0.98), smoked ≥5 pack-years (0.62, 0.43–0.89), smoked >30 years (0.86, 0.75–0.99), and smoked ≥11 years before first childbirth (0.70, 0.51–0.96). Association between smoking and MD diminished after smoking cessation, with increased odds of having mixed/dense breasts in women who quit smoking >20 years ago as compared to current smokers (1.37, 1.01–1.67). There was no association between passive smoking and MD. Conclusions: We found an inverse association between active smoking and MD.
KW - disease, health science and nursing
KW - Breast cancer risk factor
KW - Secondhand smoke
KW - Cigarette smoking
KW - Mammographic density
KW - Breast density
UR - http://www.scopus.com/inward/record.url?scp=84949527238&partnerID=8YFLogxK
U2 - 10.1007/s10552-015-0704-3
DO - 10.1007/s10552-015-0704-3
M3 - Journal article
SN - 0957-5243
VL - 27
SP - 271
EP - 280
JO - Cancer Causes & Control
JF - Cancer Causes & Control
IS - 2
ER -