Detection and significance of minimal residual disease in colorectal cancer

Abstract

Colorectal cancer (CRC) is one of the most common causes of cancer death in the developed world. Although the primary treatment for CRC is surgical, disease relapse due to minimal residual disease (MRD) following apparently curative surgery occurs in up to fifty percent of patients. Most patients who develop overt metastases beyond the regional lymph nodes eventually die of the disease. At present adjuvant chemotherapy is used to improve survival in patients with metastases to regional lymph nodes demonstrated by routine histopathology with no other evidence of spread. The ability to identify metastatic disease at an earlier stage could be of considerable benefit in directing adjuvant therapy to patients at high risk of relapse who are not identified by current methods. Several techniques have been developed for the detection of MRD, including immunohistochemical and molecular methods, however their role in clinical practise is not yet established. The purpose of this paper is to review these techniques and their potential clinical use in the management of CRC.