In compliance with the Health Insurance Portability and Accountability Act (HIPAA) regulations, PUFs have been stripped of all direct patient identifiers, de-identified according to the "Safe Harbor" rules.  The case identification number contained within is randomly assigned, and will change with each PUF version release. The PUF Case IDs are not the same across cancer sites, and cases cannot be linked across cancer sites. In the adult PUF file, pediatric patients have been excluded*, and patients 90 years of age or older are collapsed into the age group 90+ to maintain confidentiality. Facility Location and Facility Type are suppressed for cases aged 0-39. All dates have been removed and replaced with measures of elapsed time. The only date value appearing in the PUF is the year of diagnosis. The narrowest geographic unit available is that of the US Census Division in which the reporting hospital is located. Hospital identity has also been masked. For additional details, please see the document “Data De-Identification and Confidentiality Patient Case Records and CoC-Accredited Cancer Programs” posted in the PUF on-line Data Dictionary. 
(*) Note: In the 2013 PUF data, there will be four age cohorts: Pediatric (0-17), pediatric/young adult (0-39), adult (18-90+), and all aged (0-90+).