Radial Scars and Breast Cancer Risk: Update from the Nurses' Health Study (NHS) and Meta-Analysis.
Laura C Collins, Sarah Aroner, James L Connolly, Stuart J Schnitt, Graham A Colditz, Rulla M Tamimi. Beth Israel Deaconess Medical Center and Harvard Medical School, Boston; Channing Institute, Brigham and Women's Hospital, Boston; Washington University School of Medicine, St. Louis
Background: Radial scars (RS) are benign sclerosing breast lesions characterized by a central fibroelastotic nidus from which altered ducts and lobules radiate. The relationship between RS and breast cancer is controversial. In particular, estimates of subsequent breast cancer risk among women with RS have varied in the few epidemiologic studies that have investigated this association.
Design: We performed an updated analysis of the association between RS and breast cancer risk in a case-control study of benign breast disease and breast cancer risk nested within the NHS. There were 394 cases (women with a benign breast biopsy [BBB] who developed breast cancer) and 1607 controls (women with a BBB who did not develop breast cancer). BBB slides were reviewed for the presence of RS. Logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs) for the association between RS and breast cancer risk. A meta-analysis was also conducted that included data from our study and 5 prior studies of breast cancer risk in relation to RS.
Results: In the NHS update, women with RS (52 cases, 103 controls) had an increased breast cancer risk compared with those without RS (RR=2.2, 95%CI:1.5-3.1). Risk was attenuated but remained significant after adjustment for BBD category (RR = 1.74 95% CI: 1.19-2.56). The meta-analysis similarly indicated that RS are associated with an increased risk of breast cancer (RR=1.5, 95%CI:1.1-2.0) (Figure), but RS did not further increase the risk among women with either proliferative lesions without atypia or among those with atypical hyperplasia. The meta-analysis suggested that the association between RS and breast cancer risk is stronger in the first 10 yrs after BBB than ≥10 yrs (<10 yrs:RR=2.1, 95%CI:1.5-2.9; ≥10 yrs:RR=1.2, 95%CI:0.9-1.7; p for heterogeneity=0.02).
Conclusions: Our updated analysis of the NHS data and a meta-analysis indicate that RS are associated with a modest increase in the risk of subsequent breast cancer. Further, this risk is highest in the first 10 years after benign breast biopsy.
Monday, February 28, 2011 11:00 AM
Platform Session: Section C, Monday Morning