Impacto do uso de solução reveladora de linfonodos, em peças cirúrgicas, no estadiamento anatomopatológico do câncer gástrico

Abstract

Background: Gastric cancer (GC) is the fourth most frequent tumor in the world and also the second main cause of cancer-related mortality. Surgery is still the only GC curative treatment. The tumor node metastasis (TNM) staging system for GC is widely used and provides important prognostic information, especially with regards to the lymph node (LN) status. Lymph node metastasis is one of the most important criteria for staging GC. There is a link between GC prognosis and the number of metastatic LN. Special procedures have been recommended in order to improve LN analysis and metastasis detection. Aims: The aim of this study was to evaluate the impact of using a lymph node revealing solution (LRS) in lymph nodes dissection in a series of GC surgical specimens. Methods: A prospective study was performed in a consecutive series of 30 GC surgical specimens (19 men, with an average age of 59.5; 11 women, with an average age of 66.1) analyzed for pathological TNM staging. At first, LN dissection from the fat tissue was done according to the routine procedures (conventional method-CM). In order to improve LN detection this tissue was emerged in a SRL: a mixture containing 65% alcohol, 20% ether, 5% acetic acid and 10% formalin (at 10%) for 36 hours with three changes. After this procedure, a new LN dissection was performed. The number of LN by both methods were compared and analyzed. The number of LN positive and negative for metastasis was determined. Results: From the 30 surgical specimens of GC analyzed, 1,005 LN (33.5/specimen) have been dissected: 657 (21.9/specimen) by the CM and 348 (11.6/specimen) after using LRS (p= 0.0002 t-Student test). Metastasis was detected in 272 lymph nodes: 211 (7.0/specimen) by the CM and 61 (2.0/specimen) after using LRS (p= 0.0028 t-Student test). The use of LRS in lymph nodes dissection increases the number of lymph nodes in 53.0% of the specimens, and of metastasis in 28.9% of the specimens. The pN changed in five (16.7%) of the 30 cases analyzed and anatomic stage/prognostic groups in four (13.3%) of the cases. Conclusion: When compared to the conventional method, the lymph node revealing solution provides a substantial increase in the number of detected metastatic and non-metastatic lymph nodes, occasionally leading to changes in the pN staging and in the anatomic stage/prognostic group classification. This technique should be recommended, in light of its simple application procedures and low costs, as well as for facilitating the dissection process and for increasing results.