Valor diagnóstico de las proteínas uPAR en sangre para el cáncer gástrico en Guatemala / Diagnostic value of blood uPAR proteins for gastric cancer in Guatemala

El cáncer gástrico es la neoplasia más frecuente del tubo digestivo, Guatemala posee altas tasas de incidencia y mortalidad. Helicobacter pylori se ha identificado como un carcinógeno gástrico, especialmente si la infección es por cepas que expresen factor de virulencia CagA, asociado a lesiones atróficas y precancerosas. Reportes previos indican que el análisis de biopsias gástricas en pacientes positivos para H. pylori, muestran un incremento de la expresión del activador del plasminógeno uroquinasa (uPA) y su receptor (uPAR). El presente estudio tuvo como objetivo determinar el valor diagnóstico de uPAR en sangre como marcador de cáncer gástrico en Guatemala y la asociación de uPAR con la infección por de H. pylori. Se tomaron muestras sanguíneas de pacientes diagnosticados con cáncer gástrico (n = 68) y controles sanos apareados por edad y sexo (n = 136) en cuatro instituciones de la ciudad de Guatemala, se determinó uPAR e IgG anti H. pylori por metodología Elisa. Los niveles de uPAR en pacientes con cáncer estaban significativamente elevados (p < .001), no se encontró diferencia por edad, sexo, apariencia macroscópica o microscópica del tumor. El cáncer gástrico se asoció significativamente a H. pylori (p = .03). El coeficiente de correlación biserial indica una relación negativa débil (rb = -0.01, p = .443) entre uPAR y H. pylori. Las curvas ROC en uPAR reportaron alta precisión (área bajo la curva = .80) para identificar cáncer gástrico. Estos resultados sugieren que los niveles séricos de uPAR pueden tener valor en el diagnóstico cáncer gástrico.

Gastric cancer is the most frequent neoplasm of the digestive tract, Guatemala has high incidence and mortality rates. Helicobacter pylori has been identified as a gastric carcinogen, especially if the infection is by strains expressing virulence factor CagA which is associated with atrophic and precancerous lesions. Previous reports indicate that gastric biopsy analyses in H. pylori positive patients show increased expression of urokinase plasminogen activator (uPA) and its receptor (uPAR). The present study aimed to determine the diagnostic value of uPAR in blood as a marker of gastric cancer in Guatemala and the association of uPAR with infection by of H. pylori. Blood samples were collected from patients diagnosed with gastric cancer (n = 68) and healthy controls matched by age and sex (n = 136) at four institutions in Guatemala City and analyzed for uPAR and anti-H. pylori IgG. uPAR levels in cancer patients were found to be significantly elevated (p <.001), but were not influenced by age, sex, macroscopic or microscopic appearance of the tumor. Gastric cancer was significantly associated with H. pylori (p = .03). The serial correlation analysis used to determine the correlation of uPAR with H. pylori showed that there is a non-significant weak negative Pearson's correlation coefficient (r = -0.01, p = .443) between both. The ROC curves for uPAR indicated high precision (AUC = 0.80) for detection of gastric cancer. These results suggest that serum uPAR levels may be valuable in the diagnosis of gastric cancer.

Diagnostic value of the copper/zinc ratio in digestive cancer: A case control study

The aim of this study was to assess the accuracy of the copper/zinc ratio (Cu/Zn ratio) in the evaluation of a large group of patients with digestive cancer compared to gender and age-matched control subjects. A total of 282 patients was studied and separated into three groups: group I (n=75), patients with digestive cancer, group II (n=112), patients with bening digestive disease, and group II (n=95), healthy subject. Serum levels of copper and zinc were measured by atomic absorption spectrophotometry. The results showed that the serum levels of copper (mg/dL) in patients with digestive cancer (91.6 ñ27.3, p<0.05) were significantly higher than in patients with benign digestive diseasde (75.8 ñ 19.8) or healthy subjects (54.4 ñ 8.9) and the serum levels of zinc (mg/dl) were significantly lower (68.7 ñ 21.9, p<0.05) compared to benign digestive disease patients (80.1 ñ 18.7) or healthy subjects (100 ñ 11.4 mg/dl). The Cu/Zn ratio was also significantly higher in patients with digestive cancer (1.45 ñ .58, p<0.05) than those with benign digestive disease (0.95 ñ 0.28) or healthy subjects (0.55 ñ 0.13). Considering a cutoff value of 0.87, the sensitivity of the copper/zinc ratio was 82.2 percent, with a specificity of 65.7 percent, a positive predictive value of 45.8 percent and a negative predictive value of 91.3 percent. In conclusion, Cu/Zn ratio was found to be considerably higher in patients with digestive cancer compared to age-and gender-matched controls, with a sensitivity of 82.2 percent that might be useful in the evaluation of suspected malignancy