Pathological assessment of colon cancer specimens

Abstract

Pathologists play an important role in the treatment of colon cancer by undertaking a meticulous pathological assessment and producing an optimal pathological report. The specimens should be photographed and the plane of surgery described to provide a permanent record of the quality of surgery. The recommended grading system has been shown to predict patient outcome. In addition, pathologists should assess the degree of central radicality to determine whether complete mesocolic excision (CME) has been undertaken. The specimen should then be carefully dissected to ensure that all of the potential high-risk features are assessed, including the status of the non-peritonealised resection margin and the presence or absence of extramural venous invasion. All of the lymph nodes within the specimen should be examined and ancillary techniques used if required. Finally, molecular pathology is now an important component of patient management and laboratories should have access to immunohistochemistry for the mismatch repair proteins to identify microsatellite instability, and also sequencing technologies to determine the mutational status of KRAS , NRAS and BRAF genes for patients being considered for antiepidermal growth factor antibody treatment.