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2017年11月22日，《美国医学会杂志》肿瘤学分册在线发表纽约纪念医院斯隆凯特林癌症中心乳腺外科医师亚历山德拉·赫尔特起草的乳腺癌前哨淋巴结活检患者指南。 前哨淋巴结可以为指导乳腺癌治疗提供重要信息。 淋巴系统与淋巴结 淋巴结是遍布于全身的豆形结构，是免疫系统的重要组成部分。细菌或肿瘤细胞等外来颗粒，可以通过淋巴管，流向具有过滤作用的淋巴结。一些乳腺癌细胞可以通过乳腺淋巴管到达腋窝淋巴结。 什么是前哨淋巴结？ 每个腋窝通常有20～40个淋巴结，这些淋巴结彼此连接,并且与乳腺连接。一般而言，乳腺淋巴管通向淋巴结时逐步合并，最初汇入一个或若干淋巴结，然后汇入其他淋巴结。最先汇入的淋巴结，无论一个还是若干，都被称为前哨淋巴结。 如何确定前哨淋巴结？ 通过造影，可以对前哨淋巴结进行定位。由于癌细胞太小，无法随其移动而轻易追踪，因此将示踪物质注射到乳腺癌附近的淋巴管，以确定癌细胞可能转移的路径，并确定癌细胞可能落脚的前哨淋巴结。最常用的示踪物质是放射性示踪剂（同位素）锝99和蓝色染料异硫蓝，它们沿着与癌细胞相同的路径通过淋巴管，并可使前哨淋巴结在手术时被认出，因为染料或同位素将进入前哨淋巴结。虽然乳腺癌可能尚未转移到该部位，但是如果一旦发生转移，将首先在前哨淋巴结中被发现。 如何利用前哨淋巴结？ 在手术时，前哨淋巴结将被找出并切除，再被送去进行分析，以确定乳腺癌是否已经转移，这些信息可被用于改善患者结局的预估。如果手术进行于任何其他治疗之前，那么这些信息通常用于下一步治疗决策。如果手术进行于化疗之后，那么前哨淋巴结活检将提示化疗是否已对治疗前可能转移入淋巴结的乳腺癌产生影响。 重要概念 每个人都有前哨淋巴结；为了发现前哨淋巴结而进行造影，并不意味着乳腺癌已在那里。每个人都有不同数量的前哨淋巴结；你可能有一个或更多。为了确定前哨淋巴结是否存在乳腺癌，必须将其切除，并仔细评估。 关于MSKCC
关于作者 乳腺外科医师亚历山德拉·赫尔特 相关阅读 JAMA Oncol. 2017 Nov 22. [Epub ahead of print] Lymphatic Mapping and Sentinel Lymph Node Biopsy for Breast Cancer. Alexandra S. Heerdt. Memorial Sloan Kettering Cancer Center. Sentinel lymph nodes provide valuable information to guide breast cancer treatment. The Lymphatic System and Lymph Nodes Lymph nodes are kidney bean-shaped structures found throughout the body that are an important part of the immune system. Foreign particles such as bacteria or tumor cells can travel in lymphatic channels toward lymph nodes, which act as a filter. Some breast cancer cells have the ability to travel through the lymphatic channels in the breast toward the lymph nodes in the axilla (the underarm area). What Is a Sentinel Node? There are usually between 20 and 40 lymph nodes in each axilla, and these are connected with each other and with the breast. In general, lymphatic channels from the breast merge as they travel toward the lymph nodes, initially draining into 1 or several nodes before moving on to reach other nodes. This first point of drainage, whether into 1 lymph node or several, is considered the sentinel, or "guarding" lymph node or nodes. How Are Sentinel Nodes Identified? The sentinel nodes are identified through a mapping procedure. Because cancer cells are too small to be easily traced as they travel, a tracking substance is injected into the lymphatic channels near the cancer to define the potential path that cancer cells might take and to identify the sentinel node(s) where those cells might end up. The most commonly used tracking substances are a radioactive tracer (isotope) called technetium 99 and a blue dye called isosulfan blue. They follow the same route that cancer cells would through the lymphatic channels and allow the sentinel node to be identified at the time of surgery because the sentinel nodes will contain the dye or isotope. Although cancer might not yet have spread to this area, if it has spread, it will be found first in the sentinel node or nodes. How Will the Information Be Used? At the time of surgery, the sentinel node or nodes will be identified and removed. They will be analyzed to determine whether the cancer has reached them, and this information can be used to refine the patient's prognosis. The information is often used to make decisions about further treatment, if surgery is performed prior to any other treatment. If the surgical procedure is performed after chemotherapy, the sentinel node procedure will indicate whether the treatment has affected any cancer that might have been in the lymph nodes before treatment. Important Concepts Everyone has sentinel lymph nodes; conducting the mapping procedure to discover the sentinel nodes does not mean that cancer is present there. Everyone has a unique number of sentinel lymph nodes; you may have 1 or more. To determine if there is cancer present in the sentinel node, it must be removed and carefully evaluated. DOI: 10.1001/jamaoncol.2017.4000 |
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