Can the preoperative prognostic nutritional index be used as a postoperative predictor of gastric or gastroesophageal junction adenocarcinoma?

Abstract

Gastric cancer and adenocarcinoma of the esophagogastric junction are major challenges to global public health due to their high morbidity and mortality. Despite continuous improvements in treatment techniques, patient prognosis is still affected by multiple factors. The preoperative prognostic nutritional index (PNI), a simple clinical indicator, has received widespread attention in recent years. Fiflis et al conducted a systematic review and reported that a high PNI was associated with significantly better survival in patients with gastric cancer. They also found that the PNI had prognostic value in patients with cancer of different TNM stages and had a positive effect even in advanced gastric cancer patients. Although the study did not address the impact of treatment regimens and had limited data sources, the results support the validity of the PNI as a biomarker for predicting the survival of gastric cancer patients. Future studies should further standardize the calculation method of the PNI, explore its applicability in different populations, and integrate other clinical parameters to construct more accurate prediction models.

Key Words: Gastric cancer; Adenocarcinoma of the esophagogastric junction; Preoperative nutritional index; Systematic review; Clinical indicators

Core Tip: Despite continuous improvement in treatment techniques, patient prognosis with gastric cancer and adenocarcinoma of the esophageal junction is still affected by multiple factors. Fiflis et al conducted a systematic review and found that a high the prognostic nutritional index (PNI) was associated with significantly better survival in patients with gastric cancer. The results provide support for the validity of PNI as a biomarker in predicting the survival of gastric cancer patients. Future studies should further standardize the calculation method of PNI, explore its applicability in different populations, and integrate other clinical parameters to construct more accurate prediction models.

INTRODUCTION

Gastric cancer and adenocarcinoma of the esophageal junction have become major global public health challenges due to their high morbidity and mortality. Although patient survival has improved with the development of medical technology, especially chemotherapy combined with surgical strategies, prognosis is still affected by many factors[1-4]. The preoperative nutritional status of patients is of increasing concern because it not only directly affects surgical tolerance and complication rates but also is closely related to the speed of recovery and long-term survival. The preoperative prognostic nutritional index (PNI) is a simple clinical index for assessing patients' preoperative nutritional status and the degree of systemic inflammatory response that combines the serum albumin level and lymphocyte count[5-7]. In recent years, the PNI in patients with gastric cancer or adenocarcinoma of the esophagogastric junction has received increasing attention in a series of systematic review studies. The current study showed that the PNI can effectively predict the survival of patients undergoing radical gastrectomy.

Research conducted by Fiflis et al[8] from Greece revealed the role of the preoperative PNI in predicting the overall survival (OS) of patients with gastric adenocarcinoma or gastroesophageal junction adenocarcinoma following surgical intervention. They reviewed relevant studies published within the last decade, identified through extensive screening and in-depth analysis of international literature, to assess the practicality and efficacy of the PNI in guiding clinical practice[9,10]. The research team focused on a series of studies published over the past decade, identified through rigorous literature screening and quantitative evaluation, and emphasized the scientific basis and practicality of the PNI as a tool for predicting OS in patients with gastric or gastroesophageal junction adenocarcinoma.

To ensure research quality and accuracy, the study strictly adhered to the PRISMA standards, incorporating data from 16 trials comprising over 14500 patients. The majority of these studies consistently demonstrated that patients with higher preoperative PNI values had significantly better OS than those with lower PNI values. Moreover, in multivariate analyses across multiple studies, a low PNI was consistently identified as an independent adverse prognostic indicator.

PNI AS A PROGNOSTIC KEY FACTOR

This paper reported that the 5-year OS rate of patients in the high PNI group was generally greater than that of patients in the low PNI group. This finding was consistent with those of other similar studies; for instance, Hashimoto et al[11] highlighted that Japanese patients with a high PNI exhibited significantly better postoperative survival rates than those with a low PNI, and Kudou et al[12], in a study conducted at Kyushu Medical University and its affiliated institutions in Japan, reported similar results. Furthermore, demographic information and clinical characteristics provided by various studies, such as sex, age, tumor site, TNM stage, surgical type, and chemotherapy usage, were closely associated with the prognostic value of the PNI.

Notably, some studies have explored the impact of the PNI on the prognosis of patients with different TNM stages. For example, Ishiguro et al[13] reported that a high preoperative PNI was still a positive prognostic indicator even in patients with advanced gastric cancer, suggesting that the PNI may complement traditional TNM staging systems in prognostic assessment. Additionally, large-scale studies, such as that by Lee et al[14], confirmed the significant relationship between the PNI and survival rates in gastric cancer patients, indicating that the PNI is an important prognostic factor regardless of whether patients receive adjuvant chemotherapy.

LIMITATIONS OF RESEARCH

This systematic review by Fiflis et al[8] provides a comprehensive and in-depth exploration of the application of the PNI in predicting the survival rates of patients with gastric or gastroesophageal junction adenocarcinoma. This paper describes the methods used to calculate the PNI and its prognostic thresholds across various studies in detail, systematically demonstrating the relationship between the PNI and OS rates in each study. However, the review did not delve deeply into the impact of specific treatment regimens (such as adjuvant chemotherapy) on the prognostic value of the PNI, propose unified recommendations for PNI cutoff values or provide explicit plans for future research directions. Moreover, due to limited data sources, the review did not include patient groups from multiple regions or ethnic backgrounds, so the generalizability of the PNI in different populations needs to be verified in larger studies.

CONCLUSION

In summary, this systematic review and statistical analysis confirmed that the preoperative PNI is an effective biomarker for prediction of prognosis in patients with gastric cancer and gastroesophageal junction adenocarcinoma. The simplicity and rapidity of the PNI calculation can assist clinicians in preoperatively identifying patients with poor nutritional status and potentially unfavorable prognoses, enabling timely and effective nutritional support strategies and personalized treatment plans to reduce postoperative complications and prolong survival. In the future, standardization of the PNI calculation methods and cutoff values based on this research can ensure consistency and accuracy across different studies and clinical settings. Large-scale prospective multicenter studies are needed to establish prognostic thresholds for PNI that are applicable to different subtypes and stages of gastric cancer or gastroesophageal junction adenocarcinoma. Additionally, integrating other clinical parameters, such as TNM stage, inflammatory markers, blood biochemical indicators, and novel molecular biomarkers, can help researchers construct more precise prognostic models to enhance the sensitivity and specificity of survival prediction.