[133] Does the Extent of Atypical Hyperplasia in a Benign Breast Biopsy Influence the Magnitude of Breast Cancer Risk? An Update from the Nurses' Health Studies

Laura C Collins, Sarah A Aroner, Rulla M Tamimi, James L Connolly, Graham A Colditz, Stuart J Schnitt. Beth Israel Deaconess Medical Center, Boston, MA; Channing Laboratory, Brigham and Women's Hospital, Boston, MA; Washington University, St. Louis, MO

Background: Women who have had a benign breast biopsy (BBB) showing atypical hyperplasia (AH) are at increased risk for the development of breast cancer. However, the relationship between histologic type of AH (i.e., atypical ductal hyperplasia [ADH] vs. atypical lobular hyperplasia [ALH]), the extent of atypia and the magnitude of breast cancer risk are not well-defined.
Design: We conducted a case-control study of benign breast disease and breast cancer risk nested within the Nurses Health Studies. Cases were women with breast cancer who had a prior BBB (n=470). Controls were women who also had a prior BBB but who were free from breast cancer at the time the corresponding case was diagnosed (n=1845). BBB slides were reviewed by pathologists blinded to the case/control status and categorized as non-proliferative, proliferative without atypia, or AH. Those showing AH were further categorized as ADH or ALH using the criteria of Page, et al. and the number of foci of AH were recorded.
Results: The adjusted OR for breast cancer among all women with AH was 3.3 (95%CI, 2.5 - 4.3). However, the magnitude of risk differed according to histologic type of AH. The OR for the development of breast cancer among women with ALH (54 cases; 55 controls) was 6.7 (95%CI, 4.3-10.3) whereas the OR for those with ADH (52 cases; 118 controls) was 3.0 (95%CI, 2.0-4.4); this difference was statistically significant (p=0.002). Among women with ADH, there was no association between number of foci and breast cancer risk. The risk among women with ALH was minimally higher for those with >5 than for those with <5 involved TDLUs.

Odds Ratios for Breast Cancer Risk According to Extent of Atypia
 CasesControlsOR (95%CI)
ADH, 1-2 foci36733.3 (2.1-5.2)
ADH, >3 foci15412.5 (1.3-4.7)
ALH, 1-4 TDLU37396.6 (4.0-11.0)
ALH, >5 TDLU13127.0 (3.1-15.9)

Conclusions: This analysis continues to demonstrate that women with AH in a BBB are at a substantially increased risk for the development of breast cancer. The risk is greater among those with ALH than those with ADH. The extent of AH (either ADH or ALH) does not significantly contribute to breast cancer risk. The lack of a dose effect between AH and breast cancer risk indicates that the extent of AH in a BBB should not influence management decisions. In particular, women with more limited foci of AH should not be managed differently from those with greater amounts of AH.
Category: Breast

Monday, March 4, 2013 2:30 PM

Proffered Papers: Section B, Monday Afternoon


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