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

Reviewers: Kenneth Blank, MD
Source: The New England Journal of Medicine Vol. 340 No. 6 p.430 February 11, 1999

Background

Radial scars are a specific finding seen by the pathologist when examining a breast biopsy specimen. Radical scars are characterized by a fibroelastic core around which arise ducts and lobules. The significance of radial scars within a benign breast biopsy is unknown; however, many consider radial scars to be precursors of breast cancer. This hypothesis is based largely on the fact that a percent of radial scars contain areas of cancer and the similarity in appearance between cancer and a radial scar. Several small studies have failed to confirm a relation between radial scars and breast cancer, but most of these reports were limited by small patient numbers. A report published in the February 11, 1999 issue of the New England Journal of Medicine examines the relation between radial scars in benign breast lesions and the subsequent risk of breast cancer in a large group of women.

Materials and Methods

The Nurses' Health Study began in 1976 when over 120,000 nurses completed mailed questionnaires regarding the diagnosis of breast cancer as well as other medical information. In 1989, a similar study enrolled over 115,000 women. Women who reported a diagnosis of breast cancer and having had a prior benign breast biopsy were compared to a control group who also had a benign biopsy but had not developed breast cancer. The control group was matched to the breast cancer patients with respect to year the benign biopsy was performed and year of birth. For every case of breast cancer, four controls were identified.

With written consent from the study participants, the study physicians reviewed the pathologic slides from the benign breast biopsy. For both the case and control groups, the rate of obtaining slides was 34%. Thirty percent of women did not provide consent to have their slides reviewed and 50% of those that did provide permission did not have their slides reviewed because the hospital was defunct, the slides were not archived, or the hospital policy did not allow outside review.

In total, 225 women with subsequent breast cancer and 1141 controls had their benign breast biopsy slides reviewed. The slides were examined blindly- that is, the study physician did not know if breast cancer had developed. Benign lesions were classified as nonproliferative, proliferative without atypia or atypical hyperplasia. Radial scars were classified in the second group, along with intraductal papillomas, sclerosing adenosis, fibroadenomas and moderate to severe ductal hyperplasia. Radial scars were identified in 99 specimens(7%). Biopsy specimens with radial scars were further classified by size of the radial scar, the presence or absence of atypia and the number of radial scars. The median follow-up after the benign biopsy was twelve years.

Results

Women with radial scars were similar to those without radial scars in respect to many breast cancer risk factors. Specifically, there was no relation between the presence of a radial scar in the benign breast biopsy and age at menarche, parity, age at birth of first child or body mass index. However, those with radial scars were older and more likely to be postmenopausal. The group of women with radial scars in the benign breast biopsy had almost twice the risk of developing breast cancer. The risk of breast cancer was increased in both the breast with the radical scar and the contralateral breast as well. This association held after being controlled for the histologic type of the benign biopsy.

Conclusions

Radial scars present in a benign breast biopsy is associated with a significantly increased risk of subsequent breast cancer occurring in that breast. The reason radial scars are associated with breast cancer is unclear but the authors speculate that radial scars may indicate a general disturbance in the breast tissue and more specifically between the stromal and epithelial elements, that leads to radial scars, cancer or both. The authors conclude that pathologists should routinely report the presence of radial scars within benign lesions and women should be advised of their increased risk of cancer.