How complete are California Cancer Registry data?
Every cancer diagnosis made in California from 1988 onward is required by law to be reported to the California Cancer Registry (CCR). The exceptions are the common skin cancers (basal and squamous cell carcinomas) and certain non-invasive cancerous conditions of the uterine cervix. The CCR, as well as the regional registries, the cancer registrars, and others who collect cancer data for the CCR, all make a major effort to ensure that the data are as accurate and complete as possible. The level of completeness increases with time. As of December 2009, case reporting for diagnosis year 2008 was estimated to be 97% complete.
