Four percent of EDRN Registry mutation carriers developed cancer within a year after beginning follow-up in this registry; within 2 years, 10% had developed cancer. Within 2 years, 17% had developed either a cancer or a pre-malignant lesion (e.g. adenoma). Our goal is to recruit 265 mutation carriers from the EDRN High Risk Registry and Hereditary Cancer Center for the Longitudinal Serum Biorepository (LSB). Based on the cancer rates observed to date in the EDRN Registry, four years of follow-up in a group of this size would be expected to yield 53 invasive and in situ cancers and 37 benign premalignant lesions. All subjects in the serum biorepository (1)have signed consent (2) are counseled carriers (APC, BRCA1, BRCA2, CDH1, CDKN2A, MLH1, MSH2, MSH6) and (3) are enrolled in family studies through CU's Department of Preventive Medicine and/or are enrolled in the EDRN High Risk Registry. Post specimen medical history is collected annually. Serum and plasma are aliquoted for respository storage and stored in labeled cryovials in an ultra low temperature (-86C) freezer. Specimens in the LSB are available for use in EDRN biomarker development and validation studies.