Aim: Investigate the prognostic impact and clinical relevance of the sentinel node.(SN)-procedure in colon carcinoma.Patients and methods: Between May 2002 and January 2004, the SN-procedure was performed in 55 patients that underwent elective resection for clinically non-advanced colon carcinoma. A control group of 110 patients was identified from a cohort between January 2000 and April 2002. All lymph nodes were analysed by conventional haematoxylin eosin staining. All negative SNs underwent in-depth analysis using immunohistochemical-staining and automated microscopy with the Ariol-system. Patients with positive lymph nodes were offered adjuvant chemotherapy. All patients were routinely monitored at 6-month intervals and follow-up was more than 5 years.Results: The SN was successfully identified in 98% of the patients, with 94% sensitivity. In-depth analysis with immunohistochemistry and automated microscopy (Ariol-system) upstaged 3 and 4 patients respectively. When only node-negative patients were analysed, overall 5-year-survival was significantly better in the SN group (91% vs. 76%, p = 0.04). Cancer-specific-mortality was even 0% (vs. 8%, p = 0.08). Disease-free-survival was significantly improved to 96% (vs. 77%, p < 0.01).Conclusions: This study describes the prognostic impact of the SN-procedure in colon carcinoma after 5-year-follow-up: Only one patient had recurrent disease after a negative SN procedure (disease-free-survival 96%). These results indicate that the SN-procedure is of prognostic relevance and might be useful to select patients for adjuvant chemotherapy. Patients that are lymph node negative after an SN-procedure have an excellent prognosis and do not need adjuvant treatment. (c) 2013 Elsevier Ltd. All rights reserved.

Seninel node (SN) detection may be used in patients with colonic carcinoma. However, its use in patients with rectal carcinoma may be unreliable. To address this, SN detection was evaluated in patients with rectal carcinoma after short‐course preoperative radiotherapy.

PURPOSE Accurate staging in colorectal cancer is important to predict prognosis and identify patients who could benefit from adjuvant therapy. Patients with lymphatic metastasis, Stage III/Dukes C, are generally treated with adjuvant chemotherapy. Still, patients without lymphatic metastasis do have relapse as high as 27 percent in five years in Dukes B2. It is hypothesized that these patients have occult (micro)metastasis in their lymph nodes. If these (micro)metastasis can be identified, these patients might benefit from adjuvant therapy. We reviewed the literature on procedures to improve lymph node staging. METHODS An extensive literature search was performed in PubMed (www.pubmed.com). Using the reference lists, more articles were found. RESULTS We found 30 articles about sentinel node in colorectal cancer describing original series. Some groups reported several studies including the same patients. We reported their largest studies. For all other techniques, we only included key articles. CONCLUSIONS Many techniques to improve staging have been described. The finding of occult (micro)metastasis is of prognostic significance in most studies. The sentinel node technique has been recently described for use in colorectal cancer. Although it seems clear that this technique has prognostic potential, it is not yet been shown in a follow-up study. Furthermore, the finding of occult (micro)metastasis in any technique used has not been shown to be clinically significant. Whether to treat patients with adjuvant therapy if occult (micro)metastasis are found needs to be proven in future studies.

AIM:The aim of this study was to evaluate the use of Patent Blue V for identification of the sentinel node in patients with colon carcinoma. METHOD:From May 2002, 35 patients operated for colon carcinoma underwent lymphatic mapping using Patent Blue V as marker. Either directly after resection of the colon or during operation 2 ml of Patent Blue V was injected peritumourally, and the first 1 to 4 blue nodes were marked as sentinel nodes. Pathological evaluation was done on a single HE-stained section of all lymph nodes. Only if all sentinel nodes were negative for metastases, serial sectioning and additional immunohistochemical staining against keratine CK 7/8 was performed to reveal micrometastasis in the sentinel nodes. RESULTS:In 33/35 of patients at least one sentinel node was identified. In 10/33 the sentinel node was positive for metastases, and in 5/10 this was the only node containing metastases. One patient had a false negative sentinel node (accuracy 97%, sensitivity 91%). CONCLUSION:Using Patent Blue V, it is possible to identify the sentinel node in most patients with colon cancer. The results are comparable with other sentinel node studies using Lymphazurin.

Microsatellite instability (MIN) due to defective mismatch repair (MMR) genes has been reported in a subset of sporadic colorectal carcinomas and in the majority of tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC) syndrome. Among the known MMR genes, hMSH2 and hMLH1 genes are known to be predominantly altered in HNPCC patients and MIN-positive tumors. In this study, we examined MIN and the protein expression pattern of the hMSH2 and hMLH 1 by Western blot and immunohistochemistry from 32 sporadic colorectal carcinomas. MIN was observed in 6 (18%) colorectal carcinomas. Of the 6 MIN-positive tumors, one case showed no expression of either protein, 3 cases showed an absence of hMSH2 protein expression, one case showed an absence of hMLH1 protein expression and one case showed no altered expression of either protein by immunohistochemistry. The decreased expression of the hMSH2 protein in a tumor compared to the normal mucosa was also observed in 5 of the 6 MIN-positive cases by Western blot analysis. All of the MIN-negative tumors showed expression of both proteins by immunohistochemistry. Thus most of the MIN-positive tumors appear to be directely related to the altered expression of these two genes and can be diagnosed by the examination of protein expression.