Which is listed as a major risk factor for breast cancer?

Which is listed as a major risk factor for breast cancer?

• A. Radiotherapy to chest between ages 10-30
• B. Regular exercise
• C. Vitamin D deficiency
• D. High fiber diet

Answer: (A)

Exposure to ionizing radiation to the chest at a young age is a well-established major risk factor for breast cancer. Radiation damages DNA in developing breast tissue, and when exposure occurs during adolescence or early adulthood (roughly ages 10–30), the breast tissue is particularly radiosensitive, leading to a higher lifetime risk of cancer. The other options do not carry the same level of risk support. Regular exercise generally lowers breast cancer risk, not increases it. Vitamin D deficiency and a high-fiber diet have not been shown to be major risk factors for breast cancer; they are not considered drivers of increased risk in the same way chest radiation is.

Exposure to ionizing radiation to the chest at a young age is a well-established major risk factor for breast cancer. Radiation damages DNA in developing breast tissue, and when exposure occurs during adolescence or early adulthood (roughly ages 10–30), the breast tissue is particularly radiosensitive, leading to a higher lifetime risk of cancer.

The other options do not carry the same level of risk support. Regular exercise generally lowers breast cancer risk, not increases it. Vitamin D deficiency and a high-fiber diet have not been shown to be major risk factors for breast cancer; they are not considered drivers of increased risk in the same way chest radiation is.