Which of the following is NOT a known risk factor for breast cancer?

Low socioeconomic status is not recognized as a direct risk factor for breast cancer in the same way the other options are. While socioeconomic factors can influence access to healthcare, screening rates, and health overall, they do not directly increase the biological risk for developing breast cancer.

On the other hand, having a family history of breast cancer significantly elevates an individual's risk due to the genetic predispositions that can be inherited. Age over 50 is a well-established risk factor since the likelihood of developing breast cancer increases with age, particularly after this milestone. Additionally, alcohol consumption has been associated with an increased risk due to its potential effects on hormone levels and breast tissue. Each of these factors has supporting epidemiological evidence linking them directly to breast cancer risk, contrasting with the indirect role socioeconomic status plays.