What is the primary risk factor for the development of breast cancer in women of average risk?

Age is recognized as the primary risk factor for developing breast cancer in women of average risk. As women grow older, their risk of breast cancer increases significantly. This correlation is largely attributable to hormonal factors and changes that occur in the body over time. Most breast cancer cases are diagnosed in older women, particularly those aged 55 and above, which underscores the importance of age as a critical factor in breast cancer risk.

Genetic mutations, family history, and obesity are also important risk factors, but these tend to apply to specific populations or increase the risk for individuals rather than serving as broad identifiers for average risk. For instance, while genetic mutations can dramatically heighten cancer risk, they are present in a smaller percentage of the population. Family history influences risk but is also not as universally impactful as age. Obesity can contribute to breast cancer risk as well, but it does not carry the same weight as advancing age in terms of overall statistics for the average population.