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

Area of Science:

• Oncology
• Pathology
• Genetics

Background:

• Colorectal cancer (CRC) management benefits from molecular tumor testing.
• National Comprehensive Cancer Network (NCCN) guidelines recommend genetic screening for CRC specimens.
• Adherence to these guidelines ensures optimal patient care and treatment strategies.

Purpose of the Study:

• To evaluate adherence to NCCN guidelines for molecular tumor testing (e.g., immunohistochemical [IHC] testing) in colorectal cancer (CRC) specimens.
• To identify trends in CRC characteristics, physician reporting, and location impacting molecular testing.
• To assess the impact of these trends on the performance of molecular tumor testing.

Main Methods:

• Retrospective, multi-center study utilizing a centralized pathology database.
• Analysis of 2469 CRC cases diagnosed between 2016 and 2020.
• Assessment of IHC testing performance, CRC sidedness, diagnosis year, and pathologist location.

Main Results:

• IHC testing was performed on 67.5% of 2469 CRC specimens.
• No statistically significant difference in IHC testing based on CRC sidedness (p = 0.9).
• No discernible trends in IHC testing patterns among pathologists were observed.

Conclusions:

• Molecular tumor testing for CRC specimens in this community healthcare setting was inconsistent, falling below the ideal 100% adherence rate.
• No clear trends explained the likelihood of ordering IHC testing.
• Educational initiatives for pathologists and physicians managing CRC patients are recommended to improve guideline adherence.