Analysis of data from more than 100 studies, including 266,000 women, revealed 32 previously undiscovered areas in the genome where DNA variation appears to affect women’s risk of developing breast cancer.
The multinational research has used information gathered by the UK-based Breast Cancer Society Consortium over the past 15 years. New methods were used in the analysis to identify variants that may have different effects for different types of cancer. Nilanjan Chatterjee, a professor at the Johns Hopkins Bloomberg School of Public Health, “The findings from this analysis have enhanced our understanding of biology that can distinguish subtypes and increase our ability to predict women’s breast cancer risks even at the specific breast cancer subtype level,” he said.
Estrogen receptors overexpression is seen in 70% of breast cancer cases
Breast cancer is one of the most common cancers, with more than 250,000 women diagnosed each year in the United States alone. And 40,000 women succumb to the disease annually. Therefore, it is very important to have a better method to assess risks, assess screening needs, and better personalize treatment. These new variants are added to more than 170 previously discovered genetic variants that affect breast cancer risk. Seven of the 32 people found to be linked to breast cancer risk more generally by researchers were associated with estrogen receptor status.
In 70% of breast cancer cases, overexpression of estrogen receptors is observed; four of the seven degrees of tumor HER2 receptor status; HER2 The gene is often mutated in breast cancers, and about 30% of treatments target this protein. Five of the newly discovered variants seemed to be linked with a greater risk for some types of breast cancer but a lower risk for others.
“These variants are specific and can provide important information about the biology of breast cancer subtypes if followed properly,” Chatterjee said. A key difference between this study and previous similar analyzes was that previous studies focused on assessing overall risk for developing breast cancer or looked at some subtypes with relatively simple genetic traits, such as BRCA1 / 2 mutations, which significantly increase the risk of developing breast cancer in a woman. This study used a technique that allows them to evaluate genetic associations with new variants in the presence of many different background traits, such as known presence of other variants and other environmental factors.
Although this analysis was huge, including 142,798 breast cancer cases and 123,283 controls, the vast majority of women were of European descent. Chatterjee and colleagues plan to replicate their research in even larger, ethnically diverse populations in the future to identify and advance additional mutations that may not be found in the European population.