Aiello Bowles et al. BMC Cancer 2012, 12:136 http://www.biomedcentral.com/1471-2407/12/136 Page 3 of 7 Figure 1 Shows how electronic data were transferred from each Cancer Research Network site (Marshfield and Group Health) to KPCO (Kaiser Permanente Colorado) before transfer to VARI (Van Andel Research Institute). Vermont transferred data directly to VARI. Data were routed through the VARI FTP (File Transfer Protocol) server and underwent initial validation before transfer to the BRCASO database. facility IDs; and demographic data on age, height, weight, geocoded income and education, ethnicity, race, and insurance type. These data were used to prefill the BRCASO database to reduce the amount of information that needed to be collected manually from the medical records. Abstracted medical record data Each site reviewed their own electronic medical records for women eligible for the study. All abstrac- tors had previous experience abstracting cancer patients’ medical records. We developed a detailed data manual to standardize abstracted information (Additional file 1). This comprehensive manual pro- vided not only data definitions, but also preferences for which clinical report information was generally most accurate and an overall context of how the data element would be used in this study. Chart abstraction was piloted at each institution using paper forms and results for 10 cases from each site were discussed via teleconference before finalizing the manual and data- base. All electronic pre-filled data were viewable within the database, and could be edited if discrepancies were noted between administrative and chart data. Each patient was automatically marked as complete once every data field was complete, and the record was then routed to a SQL database at VARI. Clinical details abstracted from medical records included Surgical breast procedures (multiple records per per- son allowed): indication (known malignancy vs. undiag- nosed breast lesion), anesthesia type, tumor localization technique, intra-operative margin assessment, surgeon specimen orientation technique, breast reconstruction