High-risk mammographic parenchymal patterns, hormone replacement therapy and other risk factors: a case-control study.
BACKGROUND
Mammographic parenchymal patterns are of particular interest because the denser patterns reduce screening sensitivity as well as increasing breast cancer risk, and because they have been shown to be affected by exogenous oestrogens.


METHODS
We designed a case-control study comprising 200 cases with high-risk (P2 and DY) pattern and 200 controls with low-risk (N1 and P1) pattern. Mammograms were evaluated according to the Wolfe classification.


RESULTS
Parity, body mass index (BMI) and current smoking were inversely and independently associated, whereas late age of menarche and history of benign breast disease were positively associated with high-risk mammographic patterns. Current-users of hormone replacement therapy (HRT) were more than twice as likely to have a high-risk pattern than never-users (OR = 2.48, 95% CI : 1.32-4.61). Women who used HRT for more than 5 years were almost three times more likely to have a high-risk pattern than never-users (OR = 2.77, 95% CI : 1.11-6.91). Relative to never-users, women who started HRT before the menopause were more than twice as likely to have a high-risk pattern (OR = 2.53, 95% CI : 1.31-4.87).


CONCLUSIONS
Careful clinical and mammographical follow-up might be appropriate in women undergoing HRT. The HRT-induced mammographic pattern might be regarded as a new baseline and changes with respect to this new pattern could then be monitored over time.
Sala
E
E
Department of Community Medicine, Strangeways Research Laboratory, Worts Causeway, Cambridge CB1 8RN, UK. evis.sala@srl.cam.ac.uk
Warren
R
R
McCann
J
J
Duffy
S
S
Luben
R
R
Day
N
N
D000368:Aged; D001940:Breast / Q000187:drug effects* / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology / Q000517:prevention & control; D016022:Case-Control Studies; D004739:England; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008327:Mammography; D008875:Middle Aged; D016017:Odds Ratio; D017698:Postmenopause; D011446:Prospective Studies; D017584:Reproductive History; D012307:Risk Factors; D012680:Sensitivity and Specificity
D004967:Estrogens