Abstract P3-02-11: Screening Magnetic Resonance Imaging (MRI) of the breast in women at increased lifetime risk for breast cancer: A retrospective single institution study

Background: Multiple factors are associated with an increased lifetime risk of breast cancer, including inheritance of an abnormal BRCA 1/2 gene, history of lobular carcinoma in situ (LCIS) or atypical hyperplasia, family history of breast cancer or previous chest wall radiation. In 2007, the American Cancer Society released updated guidelines for breast cancer screening based on risk stratification. These guidelines added annual MRI screening to mammography for women with greater than or equal to a 20–25% lifetime risk. Breast MRI screening trials have consistently demonstrated a higher sensitivity of MRI for malignancy compared with mammography, with an additional cancer yield from MRI of approximately 3%. The purpose of this study was to evaluate MRI screening outcomes in women with an increased risk for breast cancer evaluated in an established breast subspecialty clinic within the University of Wisconsin (UW) Hospital and Clinics.

Methods: Patients (Pts) were included if they were seen by a UW breast center nurse practitioner, medical or surgical oncologist between 1/1/2007–3/1/2011 with a diagnosis code of: family history of breast or ovarian cancer, genetic susceptibility to malignant neoplasm or genetic carrier, Hodgkin's disease, LCIS, or atypical hyperplasia. Pts with a co-existing diagnosis of invasive breast cancer or ductal carcinoma in situ prior to initial encounter were excluded. Demographic information, breast cancer risk factors, estimated lifetime risk of breast cancer and screening recommendations were abstracted from the medical record. Results of subsequent breast imaging examinations (including breast MRI, diagnostic and screening mammography, and image-guided biopsies) were analyzed with the use of the mammography information system (PenRad™).

Results: Of 276 women who met the inclusion criteria, 148 underwent at least 1 screening breast MRI. The majority of MRI screened pts were premenopausal (82%) and Caucasian (96.6%) with a mean age of 42.5 (range 20–68) at their initial encounter. Eighty five percent had a first degree relative with breast cancer and 72.3% of pts undergoing MRI screening had a documented lifetime risk of breast cancer of 20% or greater using a validated model. Within this MRI-screened cohort, 18.2% had a known genetic predisposition to breast cancer. Over the time assessed, 307 MRIs were performed in the 148 pts. Biopsy was recommended and performed based on the results of the MRI in 31 of 307 exams (10%). Ten cancers were detected for a positive predictive value based on biopsy performed of 32% and an overall cancer yield of 3.3% (10 of 307 MRI exams). All cancers were stage 0 - II. All pts are currently with no evidence of disease.

Conclusion: Breast MRI has a high positive predictive value and cancer yield with an acceptable biopsy rate in a diverse group of high risk women undergoing breast MRI at an academic center outside of a clinical trial.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-11.

P4-11-21: A Retrospective Analysis of Women at Increased Lifetime Risk for Breast Cancer: Referral Patterns to Subspecialty Providers, Recommendations and Outcomes

Background: Inheritance of an abnormal BRCA 1/2 gene, a family history of breast cancer (BrCa), or a personal history of lobular carcinoma in situ (LCIS), atypical hyperplasia, or chest wall radiation can significantly increase an individual's lifetime risk for developing BrCa. In 2007, the American Cancer Society (ACS) released updated guidelines for screening in women with a lifetime risk of BrCa ≥20-25%. These guidelines added MRI screening to annual mammography. The objective of our analysis is to characterize patients referred after the release of the 2007 ACS guidelines to subspecialty providers specifically for evaluation of BrCa risk and analyze subsequent screening and risk reduction recommendations in the cohort of patients (pts) with a predicted increased lifetime risk for BrCa.

Methods: Pts seen at a single center (University of Wisconsin [UW]) between 1/2007-3/2011 by medical, surgical and/or gynecology-oncology for an increased lifetime risk of BrCa were identified by billing codes or evaluation in the UW Breast Cancer Prevention, Assessment and Tailored Health Screening (PATHS) Clinic. Pts with a personal history of BrCa prior to 1/2007 are excluded. Patients with a known genetic predisposition to BrCa, family history of breast cancer, or a personal history of LCIS, atypical hyperplasia or chest wall radiation are included in this analysis. All charts will be evaluated for documentation of the individual's lifetime risk of BrCa and method used for risk-assessment, recommended and performed screening tests, concordance with ACS screening guidelines, patient adherence to initial and subsequent screening recommendations, and uptake of risk reduction strategies. Call-back rates for additional or follow-up imaging and/or biopsy following BrCa screening and characteristics of all new BrCa diagnoses will be collected.

Results: 240 eligible pts were seen during the study period. 15% of pts referred had a known genetic predisposition to BrCa. Most pts (75%) were referred for a family history of BrCa. The majority of these pts had a predicted lifetime risk of BrCa in excess of 20%, with less than 10% of patients being referred having a lifetime risk <20%. The remaining pts were referred for a personal history of LCIS, atypical hyperplasia or previous radiation to the chest wall. Results including subspecialty provider BrCa risk assessment, screening and risk-reduction recommendations, patient uptake and adherence, outcomes of screening and characteristics of diagnosed BrCa cases will be presented.

Conclusion: Pts with a predicted increased lifetime risk for BrCa are often evaluated by oncology subspecialty providers. The primary factor related to referral is family history of BrCa. The majority of patients referred to a subspecialty provider have a calculated lifetime risk for BrCa in excess of 20%. This study evaluates provider assessment of BrCa risk and subsequent recommendations for screening and discussion of risk reduction strategies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-21.