Women who were diagnosed with invasive breast cancer 40 years of age or younger are invited to participate. The age at diagnosis is used to determine eligibility, not a woman's current age. Women who have undergone genetic testing of the BRCA1, BRCA2, p53, pTEN, e-cadherin, or LKB1 genes are eligible to participate. Young women with breast cancer are asked to: sign a consent form, submit a sample of blood, release their cancer related records, and answer some family history questions.