Final answer:
Inherited and environmental risk factors contribute to the development of breast cancer.
Step-by-step explanation:
The greatest risk for development of breast cancer can be determined by several factors, including inherited risk factors and environmental risk factors. Inherited risk factors include certain mutant genes, such as BRCA1 and BRCA2, which greatly increase the risk of breast and ovarian cancer. Environmental risk factors include certain pathogens, like hepatitis viruses, as well as nonpathogenic factors like radon, air pollution, and UV light.