Breast cancer incidence in young women by estrogen receptor status and race.

A population-based study was utilized to calculate breast cancer incidence rates in White and Black women, ages 30 to 54, according to tumor estrogen receptor status. Both racial groups had higher incidence curves for estrogen receptor negative breast cancer between ages 30 and 49. There was an excess of receptor negative cancer in young Black women, an observation that may help explain the racial disparity in breast cancer survival.