Which of the following is a common risk factor for breast cancer?

Family history and genetic mutations are recognized as significant risk factors for breast cancer. When individuals have a family history of breast cancer, particularly if close relatives such as mothers, sisters, or daughters have been diagnosed, it can indicate a genetic predisposition to the disease. Genetic mutations, such as those in the BRCA1 and BRCA2 genes, dramatically increase the risk of developing breast cancer. These mutations can be inherited and passed down through generations, highlighting the importance of a family health history in assessing an individual's risk.

In contrast, increased physical activity and a low-fat diet are generally associated with a lower risk of breast cancer rather than being risk factors. Engaging in regular physical activity and maintaining a healthy diet can contribute to overall wellness and may help mitigate some cancer risks. Additionally, younger age is typically considered a protective factor rather than a risk factor. Breast cancer is more commonly diagnosed in older individuals, making younger age a less relevant indicator for risk in this context.