Starting with the November 2020 data submission, SEER now uses "Behavior code ICD-O-3" rather than the "Behavior recode for analysis" field in SEER*Stat and any published statistics. The primary difference between the two variables is in the malignant behavior coding - the benign, borderline, and in situ coding are identical in the two fields. A cross tabulation of these variables is shown below for all cancer sites combined to demonstrate the differences.
|Behavior code for ICD-03||Behavior recode for analysis||Number of Cases in SEER Data||Percent of Cases|
|Only malignant in ICD-O-3||90,848||1.7%|
|Only malignant 2010+||13,366||0.3%|
The original rationale for using “Behavior recode for analysis" was to provide consistent coding across all SEER data from 1975 onward. This was despite changes in the reportability of cancer: in 2001, some additional tumors were identified as malignant in ICD-O-3 (coded as “Only malignant in ICD-0-3”); in 2010, additional tumors were identified as malignant (coded as “Only malignant 2010+”).
The change to “Behavior code ICD-O-3 = Malignant" is to report statistics that include all reportable malignant cases in each year despite some inconsistencies across time. As a result of this change, trends in incidence for all cancer sites combined has a jump of approximately 1% in 2001, and a much smaller impact in 2010. The extra cases that cause the jumps in 2001 and 2010 are mostly from cancer sites that are not typically reported by SEER individually, so these same jumps would not appear in any standard cancer site-specific trend reports.
Changes within SEER Products
- The default behavior selection in SEER*Stat for all November 2020 SEER databases is “Behavior code ICD-O-3 = Malignant", for prior submissions it is “Behavior recode for analysis = Malignant".
- All cases that were coded as "Behavior recode for analysis = No longer reportable in ICD-O-3" have been excluded from all databases. This includes approximately 10,000 cases diagnosed between 1975-2000, all of which had ICD-0-3 behavior of borderline and almost all of which were ovary cancers.