Breast cancer is a polygenic disease influenced by both genetic and environmental factors. Although numerous studies have examined the genetic information and breast cancer diagnoses across different ancestries and age groups, there is limited researc...
Breast cancer is a polygenic disease influenced by both genetic and environmental factors. Although numerous studies have examined the genetic information and breast cancer diagnoses across different ancestries and age groups, there is limited research addressing the varying incidence rates based on various factors. A comprehensive understanding of the relationship between breast cancer, age, and various contributing factors is crucial for developing effective strategies for early detection and prevention.
Our study statistically evaluates genetic and lifestyle factors influencing breast cancer development across ancestries and age groups of 10-year cohorts, ranging from 20 to 79. We compared European ancestry groups using White British samples from UK Biobank and Asian ancestry groups using Korean samples from Korean Genome and Epidemiology Study (KoGES).
The European ancestry group exhibited a significant risk of breast cancer on common genetic variant across the age groups from their 30s to 70s, with the highest risk in the 30s age group (OR=4.19, 95% CI 3.07-5.72, p-value = 2.95E-18) and the lowest risk observed in the 60s age group (OR=2.58, 95% CI 2.30-2.90, p-value = 6.14E-54). For the Asian ancestry group, common variant mutations posed a high risk in individuals in their 40s (OR=1.74, 95% CI 1.16-2.61, p-value = 0.0092). For rare variants, BRCA2 shows the highest risk in 30s age group (OR=12.45, 95% CI 2.49-62.29, p-value = 0.0007), BRCA1 (OR=1.82, 95% CI 1.17-2.81, p-value = 0.01) and CHEK2 (OR=2.31, 95% CI 1.24-4.28, p-value = 0.0115) in 40s age group, indicating early onset on breast cancer. Regarding obesity and lifestyle factors, in the European ancestry group, the 60s age group showed an increased breast cancer risk associated with obesity (OR = 1.29, 95% CI 1.11-1.49, p-value = 0.0008) and alcohol consumption (OR = 1.23, 95% CI 1.04-1.44, p-value = 0.0141). Conversely, physical activity was found to reduce the risk (OR = 0.73, 95% CI 0.59-0.91, p-value = 0.0042) within the same age group. In the Asian group, the highest risk of alcohol consumption was observed in their 40s (OR=2.49, 95% CI 1.28-4.84, p-value = 0.0096), and physical activity was associated with the lowest risk in their 50s (OR=0.58, 95% CI 0.38-0.88, p-value = 0.0101).
In this study, the analysis of genetic impact, including both common and rare variants, reveals that being under 50 years of age is usually a significant factor in the onset of breast cancer. Additionally, age is also identified as a critical factor in the onset of breast cancer from an environmental perspective, with varying trends observed across different factors. Future studies are warranted to explore the rare variant data in the Asian ancestry group if such data become available in the future, as this could lead to a better understanding of additional causes of breast cancer.