Questions and Answers

About the California Cancer Registry (CCR) and Cancer Case Reporting

Why does it take so long before data can be released?

There are a number of factors that make the process a long one. First, there are inherent delays in reporting cancer cases to the CCR:

  • Complete information on the case and on the first course of treatment may not be available until six months after the initial diagnosis.
  • Many cases are reported to the regional registries by multiple facilities or health care providers, and all the reports must be consolidated into a single record containing the best information available.
  • There are an increasing number of cancer patients who are diagnosed and treated in doctors' offices without ever being admitted to a hospital; more effort is required to find these cases.

The process by which CCR ensures that it produces meaningful and accurate data is also lengthy.

  • Strict quality control procedures are needed to produce complete and accurate data.  These procedures are labor intensive, yet the CCR has limited resources.
  • While the vast majority of cases are reported to the CCR within 12 months of the diagnosis date, the data cannot be published until case reporting is estimated to be at least 95 percent complete.  The last 10 percent are the hardest to complete.

What happens if data reports are released too soon?

If the data are released while incomplete, the analyses will be less useful at best, and possibly misleading. Smaller amounts of data are not as representative of what is going on in a population as larger ones. The CCR, health authorities and cancer researchers need an accurate picture of the number and kind of cancers occurring in a community before investigations and studies can try to determine what, if any, identifiable causes exist.