| PrefaceGastric cancer is more frequent malignant tumor in our country. The incidence rate and mortality rate of Gastric cancer is the highest of all malignant tumors . Surgical resection remains the only potentially curative treatment for patients with gastric cancer. The current principle of the therapy for gastric cancer is to perform a greater resection and lesser resection based on disease stage in order to improve patients'survival rate and life quality. The concept of the extended resection is to excise the local lesion enough and dissect lymph nodes and kill completely cells from the tumor. The nodal status in gastric cancer is related not only to prognosis but also to the extent of nodal dissection. But up to now, no reliable methods for the pre - or intraoperative prediction of nodal status are available in gastric cancer patients. Unnecessary extended resection resulted frequently in increasing mortality rate. In 1977, Cabanas introduced sentinel lymph node firstly. Recently, sentinel lymph node biopsy is mainly applied in breast cancer and malignant melanoma. Many reliable studies have been shown in Europe and American. Theoretically, the sentinel lymph node is the first lymph node that drains a primary tumor. So it can represent the metastasis of tumor and is the most valuable node for histological detection. Although the application of SLNB has been tried in gastric cancer for a little period. But a prediction of nodal status in pre - or intraoperation is possible. So an individualized treatment can be established by SLNB. Vital dyestuff was used in our study to show the SLNs. The SLNs were inspected by routine histologic examination and immuno-histochemical examination to detect the antigen of CK20 and CEA in order to definite the diagnostic accuracy and sensitivity of the SLN status in diagnosis of the lymph node status of the patient-Experimental Materials1. Clinical data.From June 2002 to November 2003, there were 40 patients with gastric cancer who were enrolled in this study and treated in our hospital. Their diagnosis was obtained through endoscopic and pathological inspection. All of them were peformed gastrectomy or total gastrectomy. In parallel with the gastrectomy , all patients received an extended lymph node dissection. The size and type was recorded at the time of the laparotomy. The lymph nodes were dissected in postoperation. The stage and station are defined according to the 13 th edition Japanese classification of gastric carcinoma. In the 40 patients, there are 28 men and 12 women. Their age vary from 36 to 79(average 55. 8).2. Experimental drugs.1 % Methylthioninium Chloride Injection, portion 1:1, diluted by injectable water for application in operation.CK20 antibody and CEA antibody were bought from Peking Zhong San. Non - biotin HRP detection system was bought from Zymed.Experimental Methods.1. The way of obtaining SLN.At the time of the laparotomy , regular detection for abdomen and tumor was performed. A fine needle was inserted into the subserosal layer of the stomach at 4 different sites around the primary tumor, and dye, the blue dyestuff was gently injected. The total amount of injected dye was 4 ml for each patient. All lymph nodes that were stained blue within 5 - 10 minutes after the dye injection were removed, namely SLN. The SLNs were embedded in paraffin, and continuous sections of 5 um were cut. One was stained with hematoxylin and eosin forhistologic examination. Others were stained with immunohistochemitry to detect the antigen of CK20 and CEA.2. Immunohistochemical means.Non biotin HRP detectin system which was bought from Zymed was adopted in this study. After the paraffin was removed from the section, it was liquored in 3%H2O2 for 10 minutes. Then it was liquored in PBS for 5 minutes. Drop primary antibody in it , incubate at 4C overnight. Wash with there changes of PBS for 2 minutes each. Add reagent 1 in it. Incubate at room temperature for 20 minutes. Wash with PBS there times for 2 minutes each. Add reagent 2... |
