Which of the following are recognized risk factors for developing breast cancer? (Select All that Apply.)

Rationale: A. Increasing age is one of the most significant risk factors for breast cancer. Most cases are diagnosed in women over the age of 50, although risk begins to increase after menopause. Over time, cumulative exposure to estrogen and progesterone contributes to DNA mutations in breast tissue, increasing cancer risk. Aging also reduces the efficiency of DNA repair mechanisms, making cells more susceptible to malignant changes. B. Women with dense breast tissue have more glandular and fibrous tissue relative to fat. Dense tissue is associated with a higher risk of breast cancer because there is more epithelial tissue where tumors can develop. Additionally, dense tissue can make mammogram interpretation more difficult, delaying early detection. This combination of higher risk and diagnostic challenge makes dense breast tissue an important factor to recognize. C. A family history of breast cancer, especially in a first-degree relative such as a mother, sister, or daughter, significantly increases a woman’s risk. This may reflect shared genetic factors, environmental exposures, or lifestyle patterns. Multiple affected relatives or early-onset breast cancer in the family further heighten the risk, suggesting possible hereditary cancer syndromes. D. Men can develop breast cancer, but it is extremely rare, accounting for less than 1% of all breast cancer cases. Male breast tissue is mostly inactive, which reduces the likelihood of malignant changes. Therefore, being male is not considered a significant risk factor compared to female sex. E. Regular physical activity is actually protective against breast cancer. Exercise helps maintain a healthy body weight, reduce estrogen levels, and improve immune function, all of which decrease cancer risk. It is a recommended lifestyle measure for prevention, not a risk factor. F. A low-fat diet is considered protective because it can lower circulating estrogen levels, reduce obesity, and improve overall health. Dietary patterns rich in fruits, vegetables, and lean proteins are associated with lower breast cancer risk, so low-fat diets do not contribute to risk. G. Mutations in the BRCA1 and BRCA2 genes are strongly linked to breast cancer. These genes normally function in DNA repair and tumor suppression. When mutated, they fail to correct DNA damage, leading to uncontrolled cell growth. Women with these mutations have a lifetime breast cancer risk of up to 70%, making genetic testing and counseling important for high-risk individuals.