Lymph Node Ratio for Nodal Staging in Colorectal Cancer - a Promising, but Premature Tool

10-14 regional lymph nodes, nodal staging in stage III colorectal cancer, which is solely based on the number of metastatic lymph nodes, would be inaccurate in certain circumstances. Recently, the metastatic lymph-node ratio has been suggested as an alternative tool for nodal staging in stage III colorectal cancer [2-4]. Also, after preoperative chemoradiation therapy in rectal cancer patients, the lymph-node ratio has reportedly been able to provide better stratification of patients’ prognoses than ypN staging [5]. A recent series of publications support the lymph-node ratio’s being a successful substitute for the current nodal staging in overcoming the limitation of the numeric counting system in cases of colorectal cancer. However, there are still several problems in the studies regarding the lymphnode ratio. The biggest hurdle in nodal staging with the lymph-node ratio may be that there is no consensus on a point of reference for stratification. Even though the lymph-node ratio has shown very nice stratification of patients’ prognoses in cases of stage III colorectal cancer, not all studies adapted the same point of reference. Standardization of the point of reference would be an essential step toward use of the lymph-node ratio in staging. There is no doubt that precise lymph-node staging would be an essential step toward providing accurate prognoses for colorectal cancer patients and selecting candidates for adjuvant therapy. Several studies have demonstrated the possibility of using the lymph-node ratio as a tool for more accurate nodal staging in colorectal cancer. However, many obstacles remain to be overcome before the acceptance of the lymph-node ratio in our daily practice.