#1: Solid Tumor Rules (2018)
#2: Multiple primaries
Source 1: 2018 Solid Tumor Rules
Notes: Colon, July 2019 Update
Solid Tumor Rules (2018)/Multiple primaries--Colon: Is a colorectal anastomotic site recurrence reportable, that is, a second primary, per Rule M7, third bullet, if there is no mention of mucosa but the tumor is seen on colonoscopy? See Discussion.
Colon, Rectosigmoid, and Rectum Multiple Primary Rule M7 states, Abstract multiple primaries when a subsequent tumor arises at the anastomotic site AND the subsequent tumor arises in the mucosa.
We identified tumors at the anastomotic site of previous colon primaries with no mention of mucosa in any of the available documentation. Are there any other indicators that would imply a tumor arising in the mucosa, or do we need this specific statement to consider these an additional primary?
Example: Patient has a history of invasive ascending colon adenocarcinoma diagnosed in October 2017 status post hemicolectomy followed by adjuvant chemo. There is no documentation of disease until August 2019 colonoscopy which shows a mass in the ileocolic anastomosis. Biopsy of the anastomotic site is positive for adenocarcinoma consistent with recurrence of the patient’s colonic adenocarcinoma. There is no mention of mucosa found on the pathology report.
Abstract a single primary using 2018 Colon Solid Tumor Rule M8 in the example provided as there is a subsequent tumor occurring less than 24 months in the anastomotic site, with the same histology and no mention of mucosa.
The new tumor would be a new primary when it meets any one of the criteria noted in M7. The tumor does not have to be stated to have arisen in the mucosa. M8 also has three options to determine if a single primary is present.