CS Site-Specific Factor 25

Schema Discriminator: EsophagusGEJunction (EGJ)/Stomach

Notes

**Note 1**: Since primary site codes C16.1 (fundus of stomach) and C16.2 (body of stomach) can be assigned to either the EsophagusGEJunction (EGJ) schema or the Stomach schema, this schema discriminator is needed to determine the schema to select only when the site is C16.1 or C16.2. The discriminator is coded to 981 for records with primary sites C16.3-C16.6, C16.8, or C16.9. The discriminator is coded to 982 for records with primary site C16.0. **Note 2**: In the AJCC 7th Edition, primaries of the EGJ (C16.0) and the proximal 5 cm of the stomach were moved from the Stomach chapter to the Esophagus chapter. Due to differences in the schemas for Esophagus and Stomach, a new schema was created in CSv2 to accommodate these changes. To determine whether a cancer in the fundus or body of the stomach should be coded according to the Esophagus/EGJunction or Stomach schema, it is necessary to identify the midpoint or epicenter of the tumor. In the AJCC 7th Edition, cancers whose midpoint is in the lower thoracic esophagus, EGJ, or within the proximal 5 cm of the stomach (cardia)and extending into the EGJ or esophagus, are stage-grouped similarly to adenocarcinoma of the esophagus. All other cancers with a midpoint in the stomach greater than 5 cm distal to the EGJ, or those within 5 cm of the EGJ but not extending into the EGJ or esophagus, are stage-grouped using the gastric cancer staging system. **Note 3**: For cases coded to primary site C16.1 or C16.2 and histology 8000-8152, 8154-8231, 8243-8245, 8247, 8248, 8250- 8934, 8940-9136, 9141-9582, or 9700-9701, code whether or not the tumor extends to the esophagus (crosses the EGJ) and code the stated distance of the midpoint of the tumor from the EGJ. This information will be used to determine whether the case has AJCC TNM and stage group assigned using definitions for esophagus or stomach cancers. **Note 4**: If the primary site code is C16.1 or C16.2 and involvement of the EGJ and distance from EGJ is unknown but a physician stages the case using esophagus definitions, assign code 060. Collaborative Stage will use the EsophagusGEJunction schema to assign TNM and AJCC stage. **Note 5**: Code 100 is produced by the automated conversion of records with primary site codes C16.1 and C16.2 that were originally coded in CSv1 and diagnosed before 2010.
Code Description Schema
000 No involvement of esophagus or gastroesophageal junction (EGJ) stomach
010 OBSOLETE DATA REVIEWED AND CHANGED V0204
See code 982

Tumor located in cardia or EGJ		 ERROR:
020 Esophagus or EGJ involved AND distance of tumor midpoint from EGJ 5 cm or less esophagus_gejunction
030 Esophagus or EGJ involved AND distance of tumor midpoint from EGJ more than 5 cm stomach
040 Esophagus or EGJ involved AND distance of tumor midpoint from EGJ unknown esophagus_gejunction
050 OBSOLETE DATA CONVERTED V0203
See code 000

Esophagus and EGJ NOT involved AND distance of tumor midpoint from EGJ is 5 cm or less		 ERROR:
060 Esophagus/EGJ involved AND distance of tumor midpoint from EGJ more than 5 cm from EGJ
AND physician stages case using esophagus definitions
OR
Esophagus/EGJ involvement unknown
AND distance of tumor midpoint from EGJ more than 5 cm or unknown
AND physician stages case using esophagus definitions		 esophagus_gejunction
100 OBSOLETE DATA RETAINED V0200

C16.1, C16.2 - originally coded in CSv1		 stomach
981 Primary site coded to C16.3 - C16.9
May include cases which were converted to this code from a blank		 stomach
982 Primary site coded to C16.0
May include cases which were converted to this code from a blank		 esophagus_gejunction
999 Involvement of esophagus/EGJ unknown, or no information
Not documented in patient record		 stomach