Abstract P2-11-12: Benign breast disease and breast malignancy
Authors: Ter-Minassian Monica , Somasundaram Brinda , Visvanathan Kala 
Published: March 2022

Abstract
Introduction: Women with specific types of benign breast disease (BBD) are at higher than average risk for breast cancer. Non-proliferative BBD are at lower risk (1.3-2, compared to women without BBD), proliferative without atypia (1.8), and atypical proliferative such as atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS) are at highest risk (2.5-4). We sought to categorize BBD subtypes for inclusion in a study to evaluate follow up screening and preventative care provided in a real world setting, by leveraging electronic health record and claims databases with refined diagnosis coding. Methods: We used the Kaiser Permanente Mid-Atlantic States (KPMAS) Research Data Warehouse (RDW), capturing claims and encounter data, to search for BBD among female patients with diagnosis dates from 1-1-2004 to 1-04-2020 and with at least 30 days of membership during the study period. We first selected patients with ICD-9 codes (217, 233, 610.8, 610.9), ICD-10 (D05.00-02, D05.81-82, D05.90, D24.1-2, D24.9, N60.81-2, N60.89, N60.91-2, N60.99, N62, N64.89). Filtering on IDs that capture standard diagnosis names, we included the diagnoses: benign neoplasm, intraductal papilloma, phyllodes tumor, ductal and stromal hyperplasias, dysplasia, atypical ductal and lobular hyperplasias (ADH, ALH), LCIS, and excluded fibroadenoma, sebaceous cysts, and non-specific carcinoma in situ. We calculated the time between malignant disease (DCIS or breast cancer) and the earliest BBD diagnosis in intervals: prior malignancy 31 or more days before BBD, concurrent malignancy within 30 days prior or after, and developed malignancy 31 or more days after BBD. We calculated overall survival after BC diagnosis, censored at Jan. 4, 2020. Results: We included 8670 unique patients with increased risk BBD subtypes, aged 12-93 years (median 52) at diagnosis. Patients self-reported race/ethnicity as Black (37.5%), White (28%), Asian (6%), Hispanic (1.6%), other (0.6%) and missing/unknown (25%). BBD diagnoses were first reported usually by the department of Surgery (35%), and Pathology (20%): other reporting departments include Hospitals, Radiology, Breast Health, Primary care, Ob/Gyn, and other or missing departments. Patients had more than one diagnosis: 47% benign neoplasm, 30.4% LCIS/DCIS, 12.5% intraductal papilloma, 12.9% ADH, 4% LCIS, 1.9% ALH, and the remainder with dysplasia, and phyllodes tumor or stromal hyperplasias. The benign neoplasm diagnosis was reported in 37% without another more specific diagnosis. Sixty percent, 5205 patients had no history of DCIS or BC at the time of BBD diagnosis. There were 1895 patients with DCIS (26.8% prior, 45.1% concurrent and 28.1% developed after BBD) and 3886 with BC (42.1% prior, 41.8% concurrent and 16.1% developed after BBD). For those with a breast cancer diagnosis, five-year overall survival after BC was 93%, with 649 (16.7%) deaths, median follow-up time of 6.7 yrs. Conclusion: Identifying specific BBD from the EHR can be accomplished with ICD codes and filtering on diagnosis IDs. Those with malignant disease were often diagnosed prior to or concurrent with benign disease.
Citation Format: Monica Ter-Minassian, Brinda Somasundaram, Kala Visvanathan. Benign breast disease and breast malignancy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-12.