SEER Inquiry System - Question 20210047 Details

We are preparing to send our hospitals a reminder that the behavior changes from 2 to 3 at the bottom of the basement membrane, and the T category changes from Tis to T1 at the bottom of the mucosa for colon and rectum carcinomas. We are confused by the wording of the Exception.

Distinguishing In Situ and Localized Tumors for the Digestive System

1.b. If the tumor has penetrated the basement membrane to invade the lamina propria, in which case it is localized and assigned Summary Stage 1 (localized) and for invasion of the lamina propria

Exception: Code 0 (behavior code 2) includes cancer cells confined within the glandular basement membrane (intraepithelial); includes in situ plus intramucosal carcinoma (involvement of the lamina propria and may involve but not penetrate through the muscularis mucosa) (penetration through the muscularis mucosa is behavior code 3.)

The text following (intraepithelial) is unclear. The question is: Does the text include in situ plus intramucosal carcinoma (involvement of the lamina propria and may involve but not penetrate through the muscularis mucosa) (penetration through the muscularis mucosa is behavior code 3.) mean the following:

Code 0 (behavior code 2) includes in situ plus intramucosal carcinoma. In situ plus intramucosal carcinoma is involvement of the lamina propria, which may involve (but not penetrate through) the muscularis mucosae. Penetration through the muscularis mucosa is behavior 3. If that is what the text above means, then it seems that the 2018 SEER Summary Stage Manual is saying colorectal tumors reported as: adenocarcinoma in situ, at least intramucosal adenocarcinoma in situ, high grade dysplasia/intramucosal adenocarcinoma in situ, focally intramucosal at the margin are to be coded behavior 2 and SEER Summary stage In situ (0) like the intraepithelial carcinoma tumors. However, it conflicts with the EOD Data for Colon and Rectum, Note 2, and SINQ 20210006. The text for both EOD Data for Colon and Rectum and SINQ 20210006 is clear. According to them, the above bulleted adenocarcarcinoma examples are coded SEER Summary Stage localized (1) and behavior 3. SINQ 20210006 states that: For purposes of Summary Stage, intramucosal carcinoma is a localized lesion So, intramucosal carcinoma is coded SEER Summary Stage 1 (localized) and (behavior code 3).

According to the text for EOD Primary Tumor, Colon and Rectum, Note 2 below, intramucosal, NOS involvement is invasive.

Note 2: Code 050 (behavior code 3) includes the following:

Intramucosal, NOS

Lamina propria

Mucosa, NOS

Confined to, but not through the muscularis mucosa

Thank you for your help clarifying the 2018 SEER Summary Manual Exception text above.