External validation of the new prognostic western score in predicting survival after curative resection of gastric cancer

Aim: Gastric cancers may progress differently depending on the factors affecting the prognosis. In our study, we evaluated the external validation of the new prognostic western score used to predict the surveillance of gastric cancer patients undergoing curative resection. Material and methods: The study included 139 patients over 18 years of age who underwent curative resection for gastric adenocarcinoma in our hospital between 2004 and 2015. The demographic characteristics of the patients and their albumin level, neutrophil lymphocyte ratio and pathological tumor-nodes-metastasis stage were evaluated. Results: Fifty-nine (42.4%) of the patients were female and 80 (57.6%) were male. The mean albumin value was 39±7 mg/L, and the median value of the neutrophil/lymphocyte ratio was 2.5 (1.76-4). According to the pathological tumornodes-metastasis staging, 13 cases (9.4%) were stage 1, 21 (15.1%) stage 2, 99 (71.2%) stage 3, and 6 (4.3%) stage 4. The five-year median survival of the patients was 32.5 months. Age was significantly higher in the mortality group (P=.021). In the log-rank analysis, a low albumin level, a high neutrophil lymphocyte ratio, and a high tumor-nodes-metastasis stage were statistically significant in the mortality group (P=.001, .000 and .030 respectively). In the Cox regression analysis, the only significant variable was determined as pathological stage (P=.005). Conclusion: The new prognostic western score was not significant in predicting the prognosis of gastric cancers.


Introduction
Gastric cancer ranks third in cancer-related deaths worldwide [1]. Despite advances in gastric cancer treatment, the prognosis remains poor in advanced (locally advanced or metastatic) cases [2]. Although the tumor-nodes-metastasis (TNM) staging system is used in prognosis classification, the prognosis may differ among patients at the same stage and receiving the same treatment [3,4]. Some inflammatory cells in the blood also negatively affect the prognosis with the proteins they secrete [5]. In this study, we aimed to validate the new prognostic western score in the prediction of survival in patients undergoing curative resection for gastric cancer.

Patients data
The study included 139 patients who underwent curative

Statistical analysis
The basic patient demographic data were summarized as n (%) for categorical variables and mean with standard deviation (SD) or 95% confidence interval (CI) for continuous variables.
The five-year median survival of the patients was 32.5 months.
When the mean age value was taken as cut-off, it was found to be significantly higher in the age mortality group in the logrank analysis (P = .021). In the log-rank analysis, the decrease in albumin in the mortality group was statistically significant (P = .001), but when the cut-off value of albumin was taken as 3.5 mg/dl, it was not statistically significant (P = .650). The logrank analysis also revealed that an elevated NLR was statistically significant in the mortality group (P = .000), but no statistical significance was observed at the NLR cut-off value of 2.62 (P = .612). In addition, in the same analysis, a significant difference was found in the mortality group as the stage increased both according to TNM and based on the cut-off value (P = .030 and .003, respectively) ( Figure). There was no statistically significant difference in the log-rank analysis of the new prognostic western risk scoring (P = .065). In the Cox regression analysis, the only significant variable was found to be the pathological stage (P = .005). The data of the patients are given in the table.  In the same study, the authors also suggested that the prognosis could be better predicted in gastric cancers with the new prognostic western score they developed using these prognostic markers [6]. In our study, it was seen that the TNM stage alone was significant in predicting the prognosis, but the new prognostic western score was not sufficient for this purpose.
The limitation of the study can be considered as the small number of patients and its retrospective nature.

Conclusion
External validation studies are one of the most reliable indicators for evaluating the accuracy of a system. In our study, the new prognostic western scoring system was not found significant in predicting prognosis in gastric cancer patients.

Funding
The author(s) received no finansial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interest
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.