Date of Award

January 2024

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Michaela A. Dinan

Second Advisor

Veda N. Giri


Aim: There is an increasing incidence of early-onset cancers globally, with various factors playing a crucial role in increasing cancer risk. This study explores the association between germline pathogenic/likely pathogenic variants and early-onset breast cancers (EOBC). Furthermore, the study assesses racial variations among individuals with EOBC

Methods: A retrospective study was conducted using data from the Genetics Case Conference (GCC) database, containing information on individuals diagnosed with early-onset cancers (ages 18-49) and late-onset cancers (age 50+) who underwent genetic counseling and testing. Descriptive statistics and logistic regression modeling were employed to analyze demographic characteristics, cancer types, germline genetic variants, and associations of age at onset of cancer with germline genetic variants, race, ethnicity, and BMI, specifically for early-onset breast cancer, which was the largest subset of patients.

Results: The study comprised 2458 patients, with early-onset cancers (EOC) accounting for approximately 43% of the cohort where complete data were available. Breast cancer was the most prevalent cancer type and therefore, the focus of this project. Pathogenic/likely pathogenic (P/LP) mutations were found in genes such as BRCA1, BRCA2, CHEK2, and ATM in early-onset breast cancer. There was a significant association (p <0.001) between clinical germline variants and early-onset breast cancer, with EOBC being higher among individuals with pathogenic/likely pathogenic variants (65.2%) compared to individuals without pathogenic/likely pathogenic variants (49.6%). Individuals with P/LP variants had significantly higher odds (aOR:1.97, 95% CI: 1.30-2.99) of early-onset breast cancer compared to those without P/LP variants. There were significant associations (p < 0.05) between race/ethnicity and having early-onset breast cancer, with Black/African American and Asian women demonstrating higher odds compared to White women [(aOR:1.52, 95% CI:1.11- 2.07) and (aOR:3.62 95% CI: 1.82-7.21)] respectively.

Conclusion: Findings emphasize the importance of comprehensive germline genetic testing and risk evaluation, especially for individuals diagnosed with early-onset cancers. Addressing disparities in cancer risk among different racial and ethnic groups is essential for promoting equitable access to healthcare and improving outcomes for individuals with early-onset breast cancer.


This is an Open Access Thesis.

Open Access

This Article is Open Access