Patient and tumor characteristics associated with increased mortality in young women (< or =40 years) with breast cancer.

Background: The goal of the current study is to identify predictors responsible for mortality disparities between young (< or =40 years) and older (>40 years) women with breast cancer.
Methods: From 1998 to 2006, 344 patients < or =40 years were treated for breast cancer. Cox regression models calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CI) to determine differences in breast cancer mortality in women < or =40 years versus >40 years (n = 3,252), controlling for potential confounders in univariate tests.
Results: From 1998 to 2006, 3,596 patients were treated for breast cancer; 9.6% were < or =40 years and 90.4% were >40 years. Young women were more likely to be African-American, with a family history of breast cancer, diagnosed at advanced stage, and treated by mastectomy (P < 0.05). Tumors in young women were more likely to be bilateral, T2/T3, grade III, ER/PR negative, and lymph-node positive (P < 0.01). Overall, young women (< or =40 years) with breast cancer were more likely to die compared with older women (>40 years) (aHR 1.52, CI 1.37-1.74).
Conclusions: Young women (< or =40 years) with breast cancer are diagnosed at a more advanced stage and have tumors with poor prognostic features. Young women (< or =40 years) are 52% more likely to die from breast cancer compared to older women (>40 years).