Aiello Bowles et al. BMC Cancer 2012, 12:136 http://www.biomedcentral.com/1471-2407/12/136 Page 4 of 7 Figure 2 Shows how chart abstraction data were collected from each Cancer Research Network site (KPCO [Kaiser Permanente Colorado], Marshfield, and Group Health) and Vermont and entered into a secure (HTTPS) online web application hosted by VARI. Data underwent initial validation before transfer to the BRCASO database. Surgical margins (collected per procedure): direction and distance of closest uninvolved margins by invasive carcinoma and/or DCIS, direction of margins involved (i.e. positive margin) by invasive carcinoma and/or DCIS Tumor information: tumor sizes (pathologic and as estimated by imaging prior to first treatment), size of invasive and DCIS components, presence of residual tumor in first and subsequent surgical specimens, syn- chronous tumors, final pathological diagnosis, lympho- vascular invasion, perineural invasion, HER2 result, prophylactic mastectomy pathology Lymph nodes: type of procedure (sentinel lymph node [SLN] biopsy, axillary sampling/dissection), intra- operative SLN evaluation, SLN histology, SLN and axil- lary positive and total node counts Other: Neoadjuvant treatment, imaging performed, known multi-focal and multi-centric status pre-opera- tively, prior breast cancer history Quality control Each chart abstractor was trained by the lead chart abstractor at the University of Vermont. Regular abstractor meetings occurred throughout the funding period to address specific questions. Chart abstractors could also post questions to a private SharePoint site that were answered by the lead chart abstractor or prin- cipal investigator and then disseminated to all abstrac- tors for review. After completing 1,000 charts, we reviewed frequencies of BRCASO data elements by insti- tution to check for inconsistencies, missing data, or