This is a longitudinal cohort study of young women with breast cancer. Over a 6-year period, the investigators aim to identify over 1,600 women age 40 and younger with newly diagnosed breast cancer from academic and community health care institutions. It is anticipated that 1,300 of these women will agree to participate in an observational study. Patient surveys, medical record review, and blood and tissue collection will be utilized. Women will be surveyed every 6 months for the first 3 years after diagnosis, then yearly thereafter for an additional 7 years (for a total follow-up of 10 year following diagnosis). The study will investigate short and long-term disease and treatment issues, and psychosocial concerns at baseline and in follow-up among a cohort of young women (age 40 or younger) newly diagnosed with breast cancer. The investigators aim to characterize the population of young women at diagnosis and in follow-up regarding disease and psychosocial outcomes (e.g., presentation and disease characteristics, treatment patterns and quality of care, short and long-term side effects, and psychosocial concerns including fertility, sexual functioning, and menopausal issues). The investigators will also collect tumor and blood specimens to characterize the tumors, and bank for future studies including molecular evaluations of disease characteristics, genetic variability and hormonal levels in blood. Ultimately, the investigators aim to develop predictors of outcome, and identify areas that may be amenable to intervention.