Abstract P1-09-03: Chemoprevention in patients with newly diagnosed breast cancers

Abstract Background: Chemoprevention (including tamoxifen, raloxifene, and exemestane) is a strategy to reduce breast cancer incidence in high risk women. Studies have shown at least a 50% decrease in the incidence of breast cancer in users of these drugs. Despite this benefit, the majority of high risk, unaffected women who are offered chemoprevention decline the therapy. However, there is a growing population of women who have used these agents for primary prevention, and a larger population of survivors who have used these drugs as part of their systemic treatment. The purpose of this study was to identify a cohort of women with newly diagnosed breast cancers who had utilized chemoprevention and describe their patterns of disease. Methods: The Breast Cancer Database of NYU Langone Medical Center was queried for patients who used chemopreventive drugs and developed breast cancer between 1/2010-1/2012. Patients were divided into primary and secondary chemoprevention groups (no previous history of breast cancer and previous history of breast cancer, respectively). Descriptive statistics were utilized. Results: In the study period, 24 (2%) of 996 patients had used a chemopreventive agent. For 16 of the 24 (67%), the drug was part of systemic therapy for prior breast cancer, with a median of 12 years from the initial diagnosis to the diagnosis of a second breast cancer. The primary chemoprevention group included women with risk based on family history and atypical hyperplasias. The majority of patients were diagnosed with early stage disease (88% DCIS and stage I). This likely reflects their screening behaviors. In both groups, the majority of cancers were ductal in origin. Five of the 8 patients in the primary chemoprevention group were on treatment at the time of their cancer diagnosis, while 63% of patients in the secondary group were prior users. In the secondary group, the majority of cases were contralateral second primary breast cancers, with 31% ipsilateral recurrences. Interestingly, the majority of cancers in both groups were ER/PR positive. Conclusions: Our cohort of women who used chemoprevention drugs were overwhelmingly diagnosed with early stage breast cancer, likely reflecting their commitment to screening. The majority of cancers were ER/PR positive. In this group, the choice of cancer treatment will need to be modified in light of prior hormonal treatment. Many of the patients in the secondary group were past users of prevention agents and further work is needed to clarify the duration of benefit of these drugs. In a similar vein, we look forward to research efforts to define the optimal age to initiate primary chemoprevention in high risk women. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-09-03.