reproductive
One of the best-documented risk factors for breast cancer
(and for many other cancers) is age. As seen in Figure 1, the
incidence of breast cancer is extremely low before age 30
(incidence 25 cases per 100,000), after which it increases
linearly until the age of 80, reaching a plateau of slightly less
than 500 cases per 100,000.2 If all women less than 65 years of
age are compared with women aged 65 or older, the relative
risk of breast cancer associated with increased age is 5.8