Abstract PS7-11: Benign breast disease: Temporal trends from 1967 to 2013
Authors: Degnim Amy , Ghosh Karthik , Carter Jodi M , Vierkant Robert A , Jensen Matthew R , Winham Stacey J , Hoskin Tanya L , Frost Marlene , Allers Teresa M , Gehling Denise L , Kern Mindy J , Pacheco-Spann Laura M , Vachon Celine M , Radisky Derek C , Visscher Daniel W , Sherman Mark E 
Published: February 2021

Background: Women with benign breast disease (BBD) are at increased risk of breast cancer (BC). Classic studies based on film-based mammographic screening and pathology diagnosis of surgical biopsies conducted in the 1980s established a hierarchy of increasing BC risk: non-proliferative (NP) BBD, proliferative BBD without atypia (PDWA) and atypical hyperplasia (AH). Given changes in epidemiological BC risk factors and introduction of percutaneous core needle biopsy (CNB) in mid-1990s, and later, digital mammography, we hypothesized that the patient characteristics and relative frequency of BBD diagnoses have changed over time. Accordingly, we performed a longitudinal analysis of the frequency of patient characteristics and BBD diagnoses in the Mayo BBD cohort.

Methods: Utilizing the Mayo Clinic Surgical and Pathology Indices, women ages 18 to 85 who had a BBD biopsy between 1/1/67 and 12/31/13 were identified. Breast pathologists reviewed biopsies masked to diagnoses of incident BC diagnosed in follow-up. Demographic characteristics and BC events were obtained by query of institutional data sources and participant surveys. Trends were evaluated for the following eras: 1: pre-mammogram (1967-1981), 2: pre-CNB (1982-1992), 3: CNB Transition (1993-2001), and 4: CNB (2002-2013). Demographics were formally compared across eras using chi-square tests for categorical variables and analyses of variance (ANOVAs) for continuous variables.

Results: From 1967-2013, the cohort includes 19,582 unique women with BBD. The frequency of CNB increased from eras 1-4: 0.04%, 0.6%, 51.3 %, and 88.9%, respectively. Mean age at BBD diagnosis was younger in era 1 (48.0 years) vs eras 2-4 (53.2, 52.0, and 51.8, respectively, p&lt;0.001). The percentage of biopsies diagnosed as PDWA increased from era 1-4 (25.7%, 34.3%, 35.2%, 46.2%, p&lt;0.001), as did the percentage with AH (2.4%, 5.1%, 8.6%, 12.3%, p&lt;0.001). Over eras 1-4, the percentages of women with a strong family history of BC increased (9.9%, 12.7%, 17.1%, and 29.0%, p&lt;0.001) as did mean BMI (24.8, 26.4, 27.4, and 28.6, p&lt;0.001). With a median follow-up of 10.9 years, 1,719 breast cancers have developed, with increasing proportion of noninvasive (DCIS-only) disease across eras 1-4: 15.0%, 21.1%, 21.2%, and 33.2%, p&lt; 0.001.

Conclusions: Analysis of this large, single institution BBD cohort for the 46 year period 1967-2013 demonstrates that BC risk factors among BBD patients has changed over time, with subjects demonstrating increasing age, BMI, and family history, and that the percentages of BBD classified as PDWA and AH have increased. Impact on BC risk will be further investigated.

Citation Format: Amy Degnim, Karthik Ghosh, Jodi M Carter, Robert A Vierkant, Matthew R Jensen, Stacey J Winham, Tanya L Hoskin, Marlene Frost, Teresa M Allers, Denise L Gehling, Mindy J Kern, Laura M Pacheco-Spann, Celine M Vachon, Derek C Radisky, Daniel W Visscher, Mark E Sherman. Benign breast disease: Temporal trends from 1967 to 2013 [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-11.