The Clinical Usefulness of the Sentinel Lymph Node in Rectal Cancer: Do We Believe It?

spread due to lymphatic blockage, in which case the establishment of the SLN concept seems to be not that easy [4, 5]. This paper is well organized only experimentally when it comes to the purpose of the study, but I doubt that this study contributes to the clinical usefulness of the SLN for rectal cancer treatment. We have different situations in rectal cancer that we should consider. First, the concept of a sentinel lymph in rectal cancer is still uncertain. Skipped metastasis or aberrant metastasis because of lymphatic channel occlusion or other causes, such as associated inflammation, preoperative radiation, etc., have been noted. Even very low rectal cancer needing coloanal anastomosis can uncommonly spread into the inguinal basin [6]. Second, unfortunately, the outcome and influence of micrometastasis, as one of the aims of this study, have not been definitely established for cancer prognosis in the node-negative group. We are still waiting for long-term outcomes. Third, even is sentinel LNs are identified and established, so far the treatment modality for rectal cancer has been already as surgery (total mesorectal excision or tumor related mesorectal excision), radiation and chemotherapy (FL) for both stage II and III cancers, and in my opinion, this treatment modality will not change until a newer, better treatment modality is identified or developed. Fourth, approximately 30% of rectal cancer patients have a positive regional LN at present, which means that the concept of a SLN is not meaningful in these patients. Thus, using the concept of the SLN might be timeand effort-consuming as a routine procedure, just showing the route of lymphatic drainage, and seems to have no clinical beneficial, except more careful check-ups for the patients with SLN micrometastasis in the node-negative group.