Radial scars in benign breast-biopsy specimens and the risk of breast cancer

Background Radial scars are benign breast lesions of uncertain clinical sig nificance. In particular, it is not known whether these lesions alter the r isk of breast cancer in women with benign breast disease. We conducted a ca se-control study of women who had benign breast lesions with or without rad ial scars. Methods We reviewed benign breast-biopsy specimens from 1396 women enrolled in the Nurses' Health Study, including 255 women in whom breast cancer sub sequently developed and 1141 women without subsequent breast cancer (contro ls). The controls were matched to the women with subsequent breast cancer a ccording to age and the year when the benign lesion was identified. The med ian followup after biopsy of the benign lesions was 12 years. Results Radial scars were identified in biopsy specimens from 99 women (71 percent). Most biopsy specimens with radial scars had only one radial scar (60.6 percent), and they tended to be incidental microscopical findings (me dian size, 4.0 mm). The women with radial scars had a risk of breast cancer that was almost twice the risk of the women without scars, regardless of t he histologic type of benign breast disease (relative risk, 1.8; 95 percent confidence interval, 1.1 to 2.9). Among women who had proliferative diseas e without atypia as compared with women who had nonproliferative disease, t he relative risk of breast cancer was 3.0 (95 percent confidence interval, 1.7 to 5.5) for those with radial scars and 1.5 (95 percent confidence inte rval, 1.1 to 2.1) for those without radial scars. Among women with atypical hyperplasia as compared with women with nonproliferative disease, the rela tive risk of breast cancer was 5.8 (95 percent confidence interval, 2.7 to 12.7) for those with radial scars and 3.8 (95 percent confidence interval, 2.4 to 5.9) for those without radial scars. Conclusions Radial scars are an independent histologic risk factor for brea st cancer. (N Engl J Med 1999;340:430-6.) (C) 1999, Massachusetts Medical S ociety.