The PUF only includes "analytic cases" whose initial diagnosis and/or treatment were/was performed at the reporting facility. Class of Case 00 denotes cases diagnosed at the reporting facility that did not receive any treatment at that facility. Class of Case 10-14 are cases that were initially diagnosed and provided all or part of their treatment at that facility. Class of Case codes 20-22 are those patients that were diagnosed at another facility and received all or part of their treatment at the reporting facility. If the focus of a proposed project is treatment, it would be standard practice to exclude Class of Case 00 cases from your study cohort. The Commission on Cancer does not require follow-up for Class of Case 00 cases, so they also should be excluded from survival studies.