History of smoking is associated with younger age at diagnosis of breast cancer.

Smoking tobacco has been associated with incidence, response and outcomes after treatment of some cancers. We hypothesized that tobacco use could result in an observable effect on breast cancer stage and characteristics at diagnosis. There were 6,000 patients with Tis-4, N0-3 breast cancers who presented to a comprehensive cancer center at initial diagnosis between 1970 and 2006.