RESUMO
El cáncer gástrico persiste como un problema importante de salud pública a nivel mundial. En Chile es la primera causa de mortalidad por tumores malignos. En 1962 se definió el concepto de cáncer gástrico precoz, pasando a ser una enfermedad curable si era pesquisado en estas etapas, con sobrevida de 90 por ciento o más a 5 años. La estrategia implementada en Japón para detectarlo en etapas precoces fue a través de estudios masivos en población presuntamente asintomática. Esta estrategia ha sido exitosa en los cánceres detectados en etapa precoz pero con alto costo y bajo rendimiento, no aplicable en países en desarrollo con alto riesgo. La endoscopía ha desplazado a la radiología en el estudio de las enfermedades del tubo digestivo. Otra forma de enfrentar el problema en países en desarrollo con alto riesgo, es focalizar la endoscopía en sujetos sintomáticos. Desde 1996 se desarrolla un programa de detección de cáncer gástrico mediante esta última estrategia en la comuna de La Florida, Región Metropolitana. Se presenta un análisis preliminar de 12 años de este programa y se comentan las dificultades para un diagnóstico precoz.
Gastric cancer continues to be an important worldwide public health problem. In Chile, it is the first cause of mortality by malignant tumors. In 1962 the concept of early gastric cancer was defined; it became a curable disease if detected at this stage, with a five year survival rate of at least 90 percent. The strategy implemented in Japan for early detection was through mass survey in asymptomatic population. This strategy was successful in the proportion of cancers detected at an early stage but with high cost and low efficiency, not feasible in developing countries with high risk. Endoscopy has displaced radiology as a way of assessment of digestive tube diseases. Another approach to this problem in developing countries is focusing the endoscopy in symptomatic patients. Since 1996 a gastric detection program has been in place based on this strategy in the municipality of La Florida, in Santiago. A preliminary analysis of 12 years of this program is presented and the difficulties for early diagnosis are discussed.
Assuntos
Humanos , Diagnóstico Precoce , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/prevenção & controle , Prevenção Secundária , Chile/epidemiologia , EndoscopiaRESUMO
PURPOSE: While E-cadherin in normal cells induces calcium-dependent cell-cell adhesion, in malignant cell, it plays a role in invasion and metastasis with a reduction of adhesion. Serum soluble E-cadherin is a result of the reduction of the cellular E-cadherin molecule and is found in the circulation of normal individuals, but it is particularly known to be increased in patients with malignancies. Accordingly, through checking the level of serum soluble E-cadherin in patients with gastric cancer and analyzing it in the view of clinicopathology, we investigated whether serum soluble E-cadherin could be translated into a clinicopathologic esult and used as a tumor marker. MATERIALS AND METHODS: The investigation targeted 88 patients who had been diagnosed as having gastric cancer by the Department of Surgery, St. Mary's Hospital, from October 1, 2002, to July 30, 2003, and who had under gone performed surgery. We measured the level of preoperative serum E-cadherin in the 88 patients by unsing ELISA. Among them, we collected gastric cancer tissues from 54 patients and executed immunohistochemistry for E-cadherin. The samples were compared with normal tissues in terms of both serum E-cadherin level and immunohistochemistry level, as well as with other clinicopathologic factors. RESULTS: The mean serum E-cadherin level of the 88 patients was 4368.7 ng/ml and was significantly higher than the level in 12 normal control patients, 3335.5 ng/ml (P=0.016). In terms of clinicopathology, the serum level of E-cadherin was significantly correlated with increasing age (P=0.0006) and was higher in positive venous invasion patients (P=0.0005). When the E-cadherin immunohistochemical stain was compared with the serum E-cadherin level in 54 patients, no significant statistically meaningful result was obtained (P=0.2881). However, 4 patients with serum E-cadherin levels about 6000 ng/ml were classified into the lower expression group (<80%) of E-cadherin immunohistochemicals stain. In the analysis for 36 patients who were early gastric cancer patients, the serum E-cadherin level in lymph-node-metastatic patients was higher than it was in the other patients (P=0.0442). CONCLUSION: The serum E-cadherin level in gastric cancer patients was higher than the level in normal control patients. In advanced gastric cancer patients, that the difference was increased. Also, since the E-cadherin level correlated with the serum E-cadherin level with venous invasion, it can be used as an effective tumor marker for gastric cancer. Particularly, in that the serum E-cadherin level correlated with lymph node metastasis in early gastic cancer, it can be used when a therapeutic method for early gastric cancer is selected.