| For some epithelium-originated cancers like melanoma, breast cancer, gastric cancer and colorectal cancer, regional lymph node metastasis is one of the most important prognostic indicators. If metastases exit in regional basins, the five-year survial of the patients with those cancers will decrease about 20% to 40%. Now the surgery is still the most effective treatment and routine lymph node dissection is an essential component which provides local control, staging and prognostic information and guides of sequent therapy. However lymph node dissection is flawed by its complications. On the one hand, regional metastasis indicates systemic disease, which makes lymph node dissection focused on staging rather than improving survial. On the other hand, more early-stage cancers with less possibility of regional metastases are diagnosed. Then how to correctly get the information of regional metastasis and stage with less morbidity and identify those patients without regional metastasis for whom unnecessary lymphadenectomy could be spared, is clinically crucial.Sentinel lymph node (SLN) is the first node(s) receiving the lymphatic flow from primary tumor and most likely to have metastasis first, therefore the histologic status of this node can predict the regional metastasis and determine the necessity of regional lymph node dissection. The concept was introduced by Canabas in 1977 but was developed by Morton and associates in melanoma patients in 1992. In this classic study, Patent blue V or Isosulfan blue dye was intradermally injected at the tumor site, meticulous dissection in regional basins,which was identified by preoperative lymphoscintigraphy, was then performed to retrieve blue-stained sentinel node, followed by standard regional lymph node dissection. The sentinel node was successfully identified in 82%(194/237) of lymphatic basins and the status of 99% of basins was correctly predicted by histologic status of sentinel nodes, only 2 basins had negative sentinel node but positive non-SLN in lymphadenectomy specimen, i.e. false negativity. This study demonstrated that sentinel lymph node biopsy offered a means to correctly predict the regional status without many complications. Using radioisotope tracer 99m-Technetium labeled sulfur colloid combining with intraoperative Y probe, Alex and Krag and their colleagues sequently detected the SLN's both in melanoma and breast cancer patients. In 1994, with Isosulfan blue dye Giuliano and co-workers succeeded in SLN biopsy in breast. Then in 1998 Bilchick et al. demonstrated feasibility of SLN biopsy in some solid cancers including thyroid cancer, gastrointestinal tumors and gynecologic tumors and so on. In 2000 Saha and associates reported the details of SLN biopsy in 86 colorectal cancer patients with Isosulfan blue dye, the success rate is 98. 8%, accuracy 95%, and the stage of 18% patients was changed due to micrometastases in SLN. Those studies further verified the SLN theory and demonstrated the feasibility and reliability of SLN biopsy and its clinical value.Now abroad the SLN biopsy in melanoma and breast cancer is well-developed and some prospective randomized phase III clinical trials are on the way to see whether it could be a standard of care and substitute for routine regional lymph node dissection. But as for in colorectal cancer, there are still some controversies about its value in a few studies. There are less studies concering SLN biopsy in gastric cancer, mainly focusing on its feasibility and debates exists too. Domestically, initial research of SLN biopsy started much later than abroad, there are only a very few reports regarding the SLN biopsy in breast cancer, but the methods and material flawed those studies, up to now, no report about SLN biopsy in colorectal cancer or gastric cancer has been seen.This research consists of several steps: first, using Isosulfan blue dye and intraoperative Y probe to determine the reliability and accuracy of SLN biopsy in skin melanoma and to set up the methodology; Then applied the reliable method...
|
PDF Full Text Request