What is coded as “unknown” in tumor registries?

In tumor registries, "unknown" is typically used to denote instances where specific health information cannot be determined or documented. This applies to situations where critical data related to the patient's diagnosis, treatment, or status cannot be verified or is missing. It is essential for tumor registries to maintain accurate and complete data for cancer statistics, treatment outcomes, and epidemiological studies. Hence, when certain information is either not available or cannot be established through clinical documentation, it is appropriately coded as "unknown."

This coding ensures that while the exact details may be absent, the registry still captures the existence of the case, allowing for statistical analysis without compromising the integrity of the dataset. The introduction of codes for "unknown" helps in the standardization of data reporting in cancer registries and is critical when interpreting treatment outcomes, survival rates, and other research focused on cancer trends.