Collaborative Stage

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	EsophagusGEJunction
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	EsophagusGEJunction
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	EsophagusGEJunction
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	EsophagusGEJunction
999	Involvement of esophagus/EGJ unknown, or no information Not documented in patient record	Stomach

Stomach

CS Site-Specific Factor 25Schema Discriminator: EsophagusGEJunction (EGJ)/Stomach

CS Site-Specific Factor 25
Schema Discriminator: EsophagusGEJunction (EGJ)/Stomach