Author ORCID Identifier

0009-0003-7182-885X

Date of Graduation

5-2026

Document Type

Thesis (MS)

Program Affiliation

Genetic Counseling

Degree Name

Masters of Science (MS)

Advisor/Committee Chair

Jessica Corredor

Committee Member

Banu Arun

Committee Member

Rachael Shilbauer

Committee Member

Katie Huang

Committee Member

Meagan Choates

Committee Member

Donika Saporito

Abstract

Purpose: With the widespread use of panel testing for hereditary cancer predisposition genes, many patients are identified with low or moderate cancer risk variants in genes such as RAD51C, RAD51D, and BARD1. Current literature is limited on the cancer characteristics of these patients. This study aimed to describe the cancer characteristics of patients and their relatives with RAD51C, RAD51D, or BARD1 pathogenic/likely pathogenic variants (P/LPVs).

Materials and methods: This single-institution retrospective cohort study was comprised of 65 patients with RAD51C P/LPVs, 31 patients with RAD51D P/LPVs, and 44 patients with BARD1 P/LPVs. Data was collected via chart review from patients with genetic testing completed from 2014-2025. Descriptive statistics were run using Stata. The median age of cancer diagnoses was compared to a reference value of 63, which is the median age of breast and ovarian cancer diagnosis from 2018-2022 SEER data.

Results: The median age of female primary breast cancer diagnosis for RAD51C was 48.5 (IQR 46-58, p = 0.0001), RAD51D was 43.5 (IQR 42-51, p = 0.0047), and BARD1 was 49 (IQR 45-58, p < 0.0001). The median age of ovarian cancer diagnosis was 63 (IQR 55-67, p = 0.37) for RAD51C and 66 (IQR 53-75, p = 0.67) for RAD51D. Nine patients across the entire cohort were diagnosed with breast cancer before 40. Two patients with a RAD51C P/LPV were diagnosed with ovarian cancer before 45. A recurrent variant (n = 14) was identified in predominantly white/Hispanic/Latino patients (n = 10) in the RAD51C cohort. Genetic testing in first- and second-degree relatives for the familial variant occurred at a frequency of 2.98% (n = 36), 2.28% (n = 13) and 1.99% (n = 17), for RAD51C, RAD51D, and BARD1, respectively.

Conclusion: Our study adds to the existing literature on cancer characteristics in patients with RAD51C, RAD51D, and BARD1 P/LPVs. More research is needed to identify if these findings are reproducible in a large cohort and whether screening guidelines should change to accommodate the early-onset cancers seen in this study.

Keywords

hereditary, cancer, genetics, genetic counseling, breast cancer, ovarian cancer

Download

Available for download on Monday, May 01, 2028

Share

COinS