Which of the following is NOT a high-risk criterion for breast cancer?

• A. Dense breast tissue
• B. Prior chest radiation therapy
• C. Residual lifetime risk ≥20%
• D. Initiating routine mammography at age 50 is a high-risk criterion

Answer: (D)

The key idea is distinguishing factors that genuinely raise a woman’s lifetime risk for breast cancer from routine screening guidelines. High-risk criteria are features that markedly increase risk and often lead to recommendations like supplemental MRI in addition to mammography.

Dense breast tissue increases cancer risk and also makes mammograms harder to read, so it’s considered a high-risk factor. Prior chest radiation therapy, especially in childhood or adolescence, substantially raises future breast cancer risk and is a recognized high-risk criterion. A residual lifetime risk of 20% or more is a formal threshold used to label someone as high risk and justify enhanced surveillance.

Initiating routine mammography at age 50 is a screening guideline for average-risk women, not a risk factor itself. It reflects when routine screening typically begins in many settings, rather than a factor that increases a woman’s cancer risk.

So, the option describing starting routine screening at 50 is not a high-risk criterion.