Molecular Tumor Testing on Colorectal Adenocarcinoma Specimens in a Large Community-Based Healthcare System

This study aimed to describe the adherence of National Comprehensive Cancer Network guidelines to perform genetic screening for all colorectal cancer (CRC) specimens with molecular tumor testing, eg, immunohistochemical (IHC) testing, in a large community-based healthcare setting. The study also identified trends involving characteristics of CRC, individual reporting physician, and physician location and examined the potential impact of these trends on the performance of molecular tumor testing.

This was a retrospective, multi-center study using a centralized pathology database to assess molecular testing on CRC specimens. The primary endpoint was whether tumor testing of a CRC specimen was performed. Secondary endpoints included tumor location within the colon (ie, the right or left side), year of CRC diagnosis, and location of the pathologist within the Advocate Aurora Health (AAH) system. The data were collected from 2016 to 2020.

A total of 2469 CRC cases, reviewed by 47 pathologists practicing in five separate hospitals, were identified within the AAH system for the selected five-year time period. IHC testing was performed in 1666 of these specimens (67.5%). There was no statistical difference between CRC sidedness and IHC testing performed (p = 0.9). There were no discernible features or trends for the ordering of IHC testing among different pathologists.

Molecular tumor testing for CRC specimens in this large community-based healthcare setting was inconsistent and below the ideal adherence rate of 100%. Secondary findings offered neither explanation nor trends in likelihood to send samples for IHC testing. Education would be beneficial for pathologists and all physicians who care for patients with CRC in community-based health care settings.