Practice Patterns and Trends in the Surgical Management of Mismatch Repair Deficient Colon Cancer

Area of Science:

• Oncology
• Genetics
• Surgical Oncology

Background:

• Defects in DNA mismatch repair (MMR) pathway are linked to colorectal cancer (CRC) and Lynch syndrome.
• Universal MMR testing is recommended for CRC patients to identify MMR-deficient (MMR-D) tumors.
• Lynch syndrome patients have increased risk of metachronous disease, guiding surgical recommendations.

Purpose of the Study:

• To analyze surgical management trends for MMR-D colon cancer.
• To assess factors influencing surgical procedure choices in MMR-D colon cancer.
• To evaluate adherence to guidelines for Lynch syndrome-associated colon cancer.

Main Methods:

• Retrospective analysis of nonmetastatic colorectal cancer (CRC) cases.
• Data sourced from the National Cancer Database (2018-2020).
• Evaluation of surgical procedures and influencing factors for MMR-D colon cancer.

Main Results:

• MMR-D colon cancer was identified in 19.93% of 98,112 patients.
• Extended resection was more frequent in MMR-D tumors (9.4%) vs. MMR-proficient (4.2%).
• Extended resection rates for MMR-D colon cancer were lower than expected, particularly for Lynch syndrome (9.4% vs. 25%).

Conclusions:

• Current surgical practices for MMR-D colon cancer show lower-than-expected rates of extended resection.
• Factors like insurance status, race, and treatment center impact surgical choices.
• Findings highlight a gap between guidelines and practice in managing MMR-D and Lynch syndrome-associated colon cancer.