High Systemic Immune-Inflammation Index is an Adverse Prognostic Factor for Patients With Gastroesophageal Adenocarcinoma.

OBJECTIVE

The aim of this study was to determine the clinical role of the systemic immune-inflammation index in patients with resectable adenocarcinoma of the gastroesophageal junction treated with or without neoadjuvant therapy.

BACKGROUND

Adenocarcinoma of the gastroesophageal junction is an aggressive disease, with less than 20% of overall patients surviving more than 5 years after diagnosis, while currently available clinical staging for esophageal cancer is lacking necessary accuracy. The systemic immune-inflammation index (SII) based on peripheral neutrophil, lymphocyte, and platelet counts has shown a prognostic impact in various malignancies.

METHODS

Data of consecutive patients undergoing esophagectomy (n = 320, 1992 to 2016) were abstracted. The cut point for high and low SII before neoadjuvant treatment and before surgery was calculated for illustration of the Kaplan-Meier curves. SII was used for the correlation with patients' clinicopathological characteristics as a continuous variable. Survival was analyzed with Cox proportional hazards models using clinical or pathological staging, adjusting for other known survival predictors.

RESULTS

In both neoadjuvantly treated and primarily resected patients, high SII was significantly associated with diminished overall [hazard ratio (HR) 1.3, 95% confidence interval (95% CI) 1.2-1.4; HR 1.2, 95% CI 1.2-1.3, respectively] and disease-free survival (HR 1.3, 95% CI 1.2-1.3; HR 1.2, 95% CI 1.2-1.3, respectively). In multivariable survival analysis, SII remained an independent prognostic factor for overall survival (HR 1.3, 95% CI 1.2-1.4; HR 1.2, 95% CI 1.2-1.3, respectively) and disease-free survival (HR 1.3, 95% CI 1.2-1.3; HR 1.2, 95% CI 1.2-1.3, respectively) in primarily resected and neoadjuvantly treated patients.

CONCLUSION

Elevated SII is an independent adverse prognostic factor in patients with resectable gastroesophageal adenocarcinomas with and without neoadjuvant treatment.