Prognostic value of systemic immune-inflammation index in patients with pancreatic cancer: a meta-analysis

Saturation effects of the relationship between physical exercise and systemic immune inflammation index in the short-sleep population: a cross-sectional study

BACKGROUND

Short sleep can lead to an increase in inflammation and regular exercise has been shown to have a mitigation effect. However, the association between physical exercise (PE) and inflammation in the short sleep population is an unknown and intriguing issue.

METHODS

NHANES dataset spanning the years 2007 to 2018 were analyzed. To investigate the relationship mentioned above, we carried out multivariate linear regression models controlling for sociodemographic and lifestyles factors. The systemic immune inflammation index (SII) served as a reflection of inflammatory potential, calculated as the product of platelet count, neutrophil count, and divided by the lymphocyte count. Self-reported questionnaires were used to collect sleep and exercise information.

RESULTS

A total of 14,664 participants were included for final analysis. Across the three models, PE showed significant negative associations with SII as a continuous variable [Crude Model, β (95% CI): -1.261(-1.600, -0.922), p < 0.001; Model 1, β (95% CI): -1.005(-1.344, -0.666), p < 0.001; Model 2, β (95% CI): -0.470(-0.827, -0.112), p = 0.011]. The consistent nature of the findings persisted when investigating physical exercise (PE) as a categorized variable. By two-piecewise linear regression model, we calculated a saturation effect of PE with the inflection point as 2400 MET-minutes/week.

CONCLUSION

This study suggested that performing no more than 2400 MET-minutes/week of PE was associated with lower SII levels in the short sleep population, while more PE might not bring additional benefits.

Association between lymphocyte-to-monocyte ratio and prostate cancer in men: A population-based study

Using the novel inflammatory biomarker lymphocyte-to-monocyte ratio (LMR), this work aimed to look into any potential connections between LMR and prostate cancer (PCa). A cross-sectional research investigation was conducted on 7706 male participants involved in the National Health and Nutrition Examination Survey from 2001 to 2010. Multivariate logistic regression modeling investigated the relationship between LMR levels and PCa risk. Furthermore, threshold analysis, subgroup analysis, interaction testing, and smoothed curve fitting were carried out. A significant negative correlation was seen between LMR and PCa risk (OR = 0.79, 95% CI: 0.65-0.97, P = .0002), even after controlling for potential confounding factors. A significant nonlinear negative correlation with a threshold effect and a breakpoint of 4.86 was found by smooth curve fitting between LMR and PCa. Subgroup analysis revealed a significant interaction (P for interaction = 0.0448) between the negative correlation between PCa and LMR about hypertension. Moreover, additional stratified smoothed curve fitting demonstrated a statistically significant inverse relationship between PCa risk and LMR. According to our findings, there is a substantial inverse relationship between PCa risk and LMR level. The inflammatory response-related index is quick, easy to use, and offers some clinical references. However, more extensive prospective investigations are required to confirm the involvement of LMR levels in PCa.

The diagnostic role of the systemic inflammation index in patients with immunological diseases: a systematic review and meta-analysis

The identification of novel, easily measurable biomarkers of inflammation might enhance the diagnosis and management of immunological diseases (IDs). We conducted a systematic review and meta-analysis to investigate an emerging biomarker derived from the full blood count, the systemic inflammation index (SII), in patients with IDs and healthy controls. We searched Scopus, PubMed, and Web of Science from inception to 12 December 2023 for relevant articles and evaluated the risk of bias and the certainty of evidence using the Joanna Briggs Checklist and the Grades of Recommendation, Assessment, Development, and Evaluation Working Group system, respectively. In 16 eligible studies, patients with IDs had a significantly higher SII when compared to controls (standard mean difference, SMD = 1.08, 95% CI 0.75 to 1.41, p < 0.001; I2 = 96.2%, p < 0.001; moderate certainty of evidence). The pooled area under the curve (AUC) for diagnostic accuracy was 0.85 (95% CI 0.82-0.88). In subgroup analysis, the effect size was significant across different types of ID, barring systemic lupus erythematosus (p = 0.20). In further analyses, the SII was significantly higher in ID patients with active disease vs. those in remission (SMD = 0.81, 95% CI 0.34-1.27, p < 0.001; I2 = 93.6%, p < 0.001; moderate certainty of evidence). The pooled AUC was 0.74 (95% CI 0.70-0.78). Our study suggests that the SII can effectively discriminate between subjects with and without IDs and between ID patients with and without active disease. Prospective studies are warranted to determine whether the SII can enhance the diagnosis of IDs in routine practice. (PROSPERO registration number: CRD42023493142).

Systemic immune-inflammation index (SII) and the risk of all-cause, cardiovascular, and cardio-cerebrovascular mortality in the general population

BACKGROUND

An elevated systemic immune-inflammation index (SII) is associated with higher mortality in patients with coronary artery disease and other diseases. However, the potential of SII for predicting mortality in the general population has been underexplored. Therefore, this study aimed to analyze the relationship between the SII and all-cause, cardiovascular disease, and cardiocerebrovascular disease mortality in the general population.

METHODS

This study involved 26,855 participants (≥ 18 years) from the National Health and Nutrition Examination Survey 1999-2014 who were grouped according to the SII tertiles. Survival differences between the groups were analyzed using log-rank tests and Kaplan-Meier plots. Furthermore, multivariate Cox regression and restricted cubic spline analyses were used to examine the relationship between the SII and all-cause, cardiovascular, and cardio-cerebrovascular mortality.

RESULTS

Overall, 1947 (7.425%) participants died following an average follow-up of 87.99 ± 54.04 months. Among these, 325 (1.210%) deaths were related to cardiovascular diseases and 392 (1.459%) to cardio-cerebrovascular mortality. Kaplan-Meier analysis revealed statistically significant differences in all-cause, cardiovascular, and cerebrovascular mortality between the SII tertiles (log-rank test: all P < 0.001). Multi-adjusted models showed that participants in the highest tertile of SII had a higher risk of death from all-cause (hazard ratio [HR] = 1.48, 95% confidence interval [CI] 1.48-1.48) and cardiovascular mortality (HR = 1.60, 95% CI 1.60-1.61) compared with those in the lowest tertile. In addition, the restricted cubic spline curve indicated a nonlinear association between SII and all-cause mortality (P < 0.001), with threshold value of SII at 18.284. There was a 15% decrease in the risk of all-cause mortality for each twofold change in SII on the left flank (HR = 0.85, 95% CI 0.69-1.05) and a 42% increase (HR = 1.42, 95% CI 1.23-1.64) on the right flank of the inflection point. In addition, the risk of cardiovascular mortality increased nonlinearly by 39% per twofold change in SII (HR = 1.39, 95% CI 1.07-1.81). There was also a nonlinear increase in the risk of cardio-cerebrovascular mortality per twofold change in SII (HR = 1.29, 95% CI 1.00-1.66).

CONCLUSIONS

In the general population, the SII was significantly associated with all-cause, cardiovascular, and cardio-cerebrovascular mortality, regardless of the established risk factors.

Prognostic and clinicopathological significance of Systemic Immune-Inflammation Index in cancer patients receiving immune checkpoint inhibitors: a meta-analysis

BACKGROUND

Among malignant neoplasm patients taking immune checkpoint inhibitors (ICIs), it remains unknown how the systemic immune-inflammation index (SII) affects their clinical prognosis. We therefore performed the present meta-analysis by collecting the most recent data, so that SII's prognostic value among ICI-receiving carcinoma patients could be fully clarified.

METHODS

For the prognostic significance evaluation of SII in ICI-receiving carcinoma patients, the combined hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

The number of studies enrolled in the present meta-analysis totaled 17, where 1,990 patients were involved. Among the ICI-treated carcinoma patients, a high SII was linked significantly to inferior overall survival (OS) (HR = 2.62, 95% CI = 1.76-3.90), as well as progression-free survival (PFS) (HR = 2.09, 95% CI = 1.48-2.95) (p both <.001). Contrastively, SII was linked insignificantly to the age (OR = 1.08, 95% CI = 0.39-2.98, p = .881), gender (OR = 1.01, 95% CI = 0.59-1.73, p = .959), lymph node (LN) metastasis (OR = 1.41, 95% CI = 0.92-2.17, p = .117), or metastatic site quantity (OR = 1.49, 95% CI = 0.90-2.46, p = .119).

CONCLUSION

There are prominent associations of elevated SII with the poor survival outcomes (both short- and long-terms) among the ICIreceiving carcinoma patients. SII has potential as a reliable and cheap prognostic biomarker in the clinic for carcinoma patients receiving ICIs.

Prognostic and clinicopathological impacts of systemic immune-inflammation index on patients with diffuse large B-cell lymphoma: a meta-analysis

Background

The systemic immune-inflammation index (SII) represents the immunoinflammatory score and can be considered as a prognostic marker; however, its relevance to the prognosis in patients with diffuse large B-cell lymphoma (DLBCL) remains unclear.

Objectives

The present meta-analysis was conducted to comprehensively evaluate the relationship between the SII and prognosis in patients with DLBCL.

Design

This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Data sources and methods

The PubMed, Web of Science, Embase, and Cochrane Library databases were comprehensively searched from inception to 16 March 2023. We calculated combined hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the prognostic significance of the SII for overall survival (OS) and progression-free survival (PFS) in DLBCL. In addition, this study determined odds ratios (ORs) and their 95% CIs to evaluate the correlation of SII with the clinicopathological features of DLBCL.

Results

Five articles including 592 cases were enrolled in the current meta-analysis. According to our combined findings, the higher SII significantly predicted worse OS (HR = 3.87, 95% CI: 2.48-6.04, p < 0.001) together with inferior PFS (HR = 2.38, 95% CI: 1.12-5.08, p = 0.024) in DLBCL. Furthermore, a high SII was significantly correlated with B symptoms (OR = 2.52, 95% CI: 1.66-3.81, p < 0.001), III-IV Ann Arbor stage (OR = 2.86, 95% CI: 1.84-4.45, p < 0.001), high-intermediate/high National Comprehensive Cancer Network International Prognostic Index (OR = 2.25, 95% CI: 1.52-3.31, p < 0.001), increased neutrophil-to-lymphocyte ratio (OR = 33.76, 95% CI: 17.18-66.35, p < 0.001), and increased platelet-to-lymphocyte ratio (OR = 44.65, 95% CI: 5.80-343.59, p < 0.001). Nonetheless, the SII was not significantly related to sex, age, lactic dehydrogenase level, Eastern Cooperative Oncology Group performance status, or histology.

Conclusion

According to this meta-analysis, the higher SII dramatically predicted inferior OS and PFS of DLBCL. Furthermore, an increased SII significantly correlated with some clinicopathological features representing the disease progression of DLBCL.

Trial registration

The protocol was registered in INPLASY under the number INPLASY202380106.

Systemic immune-inflammation index and the survival of hepatocellular carcinoma patients after transarterial chemoembolization: a meta-analysis

The systemic immune-inflammation index (SII), derived from neutrophil, platelet, and lymphocyte counts, has been associated with prognosis of patients with cancer. We performed a meta-analysis to evaluate the association between pretreatment SII and survival of patients with hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE). Cohort studies were identified by search of PubMed, Embase, Web of Science, CNKI, and Wanfang databases. Pooling the results was achieved with a random-effect model that incorporates potential heterogeneity between studies. Nine studies including 3557 patients with HCC contributed to the meta-analysis. Compared to patients with a lower SII, HCC patients with a higher pretreatment SII had poor overall survival (OS, hazard ratio [HR] 1.66, 95% confidence interval [CI] 1.25-2.21, p < 0.001; I2 = 80%) and poor progression-free survival (PFS, HR 1.28, 95% CI 1.05-1.56, p = 0.01; I2 = 0%) after TACE treatment. Further subgroup analyses confirmed a significant association between a high pretreatment SII and poor OS after TACE, which was not significantly affected by study country, sample size, age of the patients, cutoff values for SII, and adjustment of Child-Pugh score or alpha fetoprotein (p for subgroup effect all < 0.05). However, a higher SII was associated with poor OS in studies with follow-up duration ≤ 24 months (HR 1.94, 95% CI 1.39-2.72, p < 0.001), but the association was not statistically significant in studies with follow-up duration > 24 months (HR 1.27, 95% CI: 0.96-1.68, p = 0.09). A higher pretreatment SII was correlated with poor survival of HCC patients after TACE. A preliminary measurement of SII may be valuable for the prediction of the prognosis in HCC patients after TACE.

Systemic inflammation index, disease severity, and mortality in patients with COVID-19: a systematic review and meta-analysis

Introduction

An excessive systemic pro-inflammatory state increases the risk of severe disease and mortality in patients with coronavirus disease 2019 (COVID-19). However, there is uncertainty regarding whether specific biomarkers of inflammation can enhance risk stratification in this group. We conducted a systematic review and meta-analysis to investigate an emerging biomarker of systemic inflammation derived from routine hematological parameters, the systemic inflammation index (SII), in COVID-19 patients with different disease severity and survival status.

Methods

A systematic literature search was conducted in PubMed, Web of Science, and Scopus, between the 1st of December 2019 and the 15th of March 2023. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development and Evaluation, respectively (PROSPERO registration number: CRD42023420517).

Results

In 39 studies, patients with a severe disease or non-survivor status had significantly higher SII values on admission compared to patients with a non-severe disease or survivor status (standard mean difference (SMD)=0.91, 95% CI 0.75 to 1.06, p<0.001; moderate certainty of evidence). The SII was also significantly associated with the risk of severe disease or death in 10 studies reporting odds ratios (1.007, 95% CI 1.001 to 1.014, p=0.032; very low certainty of evidence) and in six studies reporting hazard ratios (1.99, 95% CI 1.01 to 3.92, p=0.047; very low certainty of evidence). Pooled sensitivity, specificity, and area under the curve for severe disease or mortality were 0.71 (95% CI 0.67 to 0.75), 0.71 (95% CI 0.64 to 0.77), and 0.77 (95% CI 0.73 to 0.80), respectively. In meta-regression, significant correlations were observed between the SMD and albumin, lactate dehydrogenase, creatinine, and D-dimer.

Discussion

Our systematic review and meta-analysis has shown that the SII on admission is significantly associated with severe disease and mortality in patients with COVID-19. Therefore, this inflammatory biomarker derived from routine haematological parameters can be helpful for early risk stratification in this group.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023420517.

Prognostic significance of systemic immune-inflammation index in patients with ovarian cancer: a meta-analysis

Background

The prognosis of several malignancies has been influenced by the systemic immune-inflammation index (SII); however, its association with the prognostic outcome of ovarian cancer (OC) remains controversial. The present meta-analysis focused on the systemic and comprehensive identification of the role of SII in predicting OC prognosis.

Methods

We searched the Web of Science, PubMed, Cochrane Library, Embase, and China National Knowledge Infrastructure (CNKI) from inception until March 6, 2023. To predict the prognostic value of SII for overall survival (OS) and progression-free survival (PFS) in patients with OC, we calculated pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CIs).

Results

The meta-analysis included six studies involving 1546 patients. The combined results showed that a high SII was significantly associated with poor OS (HR=2.70, 95% CI=1.98-3.67, p<0.001) and poor PFS (HR=2.71, 95% CI=1.78-4.12, p<0.001) in OC patients. These results were confirmed using subgroup and sensitivity analyses.

Conclusion

Our results concluded that a high SII significantly predicted poor OS and PFS in patients with OC. Therefore, it can be speculated that the SII may have an independent effect on the prognosis of OC.

Prognostic value of pretreatment skeletal muscle index in pancreatic carcinoma patients: A meta-analysis

BACKGROUND

The association between pretreatment skeletal muscle index (SMI) and long-term survival of pancreatic carcinoma patients remains unclear up to now.

METHODS

The PubMed, Web of Science and EMBASE databases were searched up to March 1, 2022 for relevant studies. The primary and secondary outcomes were overall survival and progression-free survival, respectively. The hazard ratios (HRs) and 95% confidence intervals (CIs) were combined to assess the relationship between pretreatment SMI and prognosis of pancreatic carcinoma patients. All statistical analysis was conducted by STATA 15.0 software.

RESULTS

Twenty retrospective studies involving 3765 patients were included. The pooled results demonstrated that lower pretreatment SMI was significantly related to poorer overall survival (HR = 1.42, 95% CI: 1.25-1.62, P < .001) and progression-free survival (HR = 1.41, 95% CI: 1.08-1.84, P = .012). Besides subgroup analysis based on the treatment (non-surgery vs surgery) and tumor stage (advanced vs early stage) showed similar results.

CONCLUSION

Pretreatment SMI could serve as a promising and reliable prognostic factor for pancreatic carcinoma patients and lower pretreatment SMI predicted worse prognosis.

Stereotactic Body Radiotherapy as an Effective Treatment for Pancreatic Cancer

Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dose to the tumor with minimal toxicity. Although magnetic resonance imaging (MRI)-guided SBRT appears to be a promising approach in the modern era, X-ray image-guided SBRT is still used worldwide for pancreatic cancer. This study aims to evaluate the results of X-ray image-guided SBRT in patients with locally advanced pancreatic cancer (LAPC). Methodology Medical records of 24 patients with unresectable LAPC who underwent X-ray image-guided SBRT between 2009 and 2022 were retrospectively evaluated. SPSS version 23.0 (IBM Corp., Armonk, NY, USA) was utilized for all analyses. Results The median age was 64 years (range = 42-81 years), and the median tumor size was 3.5 cm (range = 2.7-4 cm). The median total dose of SBRT was 35 Gy (range = 33-50 Gy) in five fractions. After SBRT, 30% of patients showed complete and 41% showed partial response, whereas 20% had stable disease and 9% had progression. Median follow-up was 15 months (range = 6-58 months). During follow-up, four (16%) patients had local recurrence, one (4%) had a regional recurrence, and 17 (70%) had distant metastasis (DM). The two-year local control (LC), local recurrence-free survival (LRFS), overall survival (OS), and DM-free survival (DMFS) rate was 87%, 36%, 37%, and 29%, respectively. In univariate analysis, a larger tumor size (>3.5 cm) and higher cancer antigen 19-9 level (>106.5 kU/L) significantly decreased the OS, LRFS, and DMFS rates. No severe acute toxicity was observed. However, two patients had severe late toxicity as intestinal bleeding. Conclusions X-ray image-guided SBRT provides a good LC rate with minimal toxicity for unresectable LAPC. However, despite modern systemic treatments, the rate of DM remains high which plays a major role in survival.

Prognostic value of the pretreatment systemic immune-inflammation index in patients with prostate cancer: a systematic review and meta-analysis

BACKGROUND

The systemic immune-inflammation index (SII) is a novel biomarker to predict the prognosis of some malignant tumors based on neutrophil, platelet, and lymphocyte counts. Evidence is scarce about the prognostic value of SII for prostate cancer patients. This systematic review and meta-analysis was conducted to explore the prognostic value of the SII in prostate cancer.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library (CENTRAL) databases were searched to determine eligible studies from inception to August 15, 2022. Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted to pool the results. Statistical analyses were conducted by using Stata 17.0 software.

RESULTS

A total of 12 studies with 8083 patients were included. The quantitative synthesis showed that a high SII was related to poor overall survival (OS) (HR = 1.44, 95% CI 1.23-1.69, p < 0.001). Furthermore, a subgroup analysis showed that a high SII was associated with poor OS in the groups of any ethnicity, tumor type, and cutoff value. An increased SII was also associated with inferior progression-free survival (PFS) (HR = 1.80, 95% CI 1.27-2.56, p = 0.001). In the subgroup analysis, a high SII value was related to poor PFS in Asian patients (HR = 4.03, 95% CI 1.07-15.17, p = 0.04) and a cutoff value > 580 (HR = 1.19, 95% CI 1.04-1.36, p = 0.01).

CONCLUSION

Based on the current evidence, a high pretreatment SII may be associated with poor OS and PFS. The SII may serve as an important prognostic indicator in patients with prostate cancer. More rigorously designed studies are needed to explore the SII and the prognosis of prostate cancer.

Prognostic significance of pretreatment systemic immune-inflammation index in patients with prostate cancer: a meta-analysis

BACKGROUND

The SII (systemic immune-inflammation index) has been extensively reported to have a prognostic value in prostate cancer (PCa), despite the unconformable results. The purpose of this meta-analysis is to quantify the effect of pretreatment SII on survival outcomes in patients with PCa.

METHODS

The following databases were searched: Web of Science, Cochrane Library, PubMed, Embase, and China National Knowledge Infrastructure (CNKI). For exploration of the SII's correlations with the overall survival (OS) and the progression-free survival/biochemical recurrence-free survival (PFS/bRFS) in PCa, the pooled hazard ratios (HRs) were assessed within 95% confidence intervals (CIs).

RESULTS

The present meta-analysis covered 10 studies with 8133 patients. Among the PCa population, a high SII was linked significantly to poor OS (HR = 2.63, 95% CI = 1.87-3.70, p < 0.001), and worse PFS/bRFS (HR = 2.49, 95% CI = 1.30-4.77, p = 0.006). However, a high SII was not linked significantly to T stage (OR = 1.69, 95% CI = 0.86-3.33, p = 0.128), the metastasis to lymph node (OR = 1.69, 95% CI = 0.69-4.16, p = 0.251), age (OR = 1.41, 95% CI = 0.88-2.23, p = 0.150), or the Gleason score (OR = 1.32, 95% CI = 0.88-1.96, p = 0.178).

CONCLUSIONS

For the PCa sufferers, the SII might be a promising prognostic biomarker, which is applicable to the high-risk subgroup identification, and provide personalized therapeutic strategies.

Predictive value of SII and sd-LDL for contrast-induced acute kidney injury in STEMI patients undergoing percutaneous coronary intervention

Aim: To investigate the relationship between the incidence of contrast-induced acute kidney injury (CI-AKI) and the level of small dense low-density lipoprotein (sd-LDL) and systemic immune-inflammation index (SII) in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing emergency percutaneous coronary intervention (PCI), and to further compare the predictive values of SII, sd-LDL and their combination for CI-AKI. Methods: A total of 674 patients were assigned to a training and a validation cohort according to their chronological sequence. The baseline characteristics of the 450 patients in the training cohort were considered as candidate univariate predictors of CI-AKI. Multivariate logistic regression was then used to identify predictors of CI-AKI and develop a prediction model. The predictive values of SII, sd-LDL and their combination for CI-AKI were also evaluated. Results: Multivariate logistic regression analysis showed that age, left ventricular ejection fraction (LVEF), sd-LDL, uric acid, estimated glomerular filtration rate (eGFR) and SII were predictors of CI-AKI. The area under the curve (AUC) of the prediction model based on the above factors was 0.846 [95% confidence interval (CI) 0.808–0.884], and the Hosmer-Lemeshow test (P = 0.587, χ2 = 6.543) proved the goodness of fit of the model. The AUC combining SII with sd-LDL to predict CI-AKI was 0.785 (95% CI 0.735–0.836), with a sensitivity of 72.8% and a specificity of 79.8%, and was statistically significant when compared with SII and sd-LDL, respectively. The predictive efficiency of combining SII with sd-LDL and SII were evaluated by improved net reclassification improvement (NRI, 0.325, P < 0.001) and integrated discrimination improvement (IDI, 0.07, P < 0.001). Conclusions: Both SII and sd-LDL can be used as predictors of CI-AKI in STEMI patients undergoing emergency PCI, and their combination can provide more useful value for early assessment of CI-AKI.

The prognostic value of systemic immune-inflammation index in surgical esophageal cancer patients: An updated meta-analysis

Purpose

To identify the prognostic role of systemic immune-inflammation index (SII) in esophageal cancer patients receiving operation.

Methods

The PubMed, EMBASE, Web of Science, Cochrane Library, WanFang and CNKI electronic databases were searched up to February 17, 2022 for relevant studies. The hazard ratios (HRs) and 95% confidence intervals (CIs) were combined to assess the association between SII and prognosis in surgical esophageal cancer patients. The primary outcome was overall survival (OS) and secondary outcomes were progression-free survival (PFS) and cancer-specific survival (CSS). All statistical analyses were conducted by STATA 15.0 software.

Results

A total of nine retrospective studies involving 3,565 participates were included. The pooled results indicated that high SII was significantly related with poor OS (HR = 1.58, 95% CI: 1.23–2.02, P < 0.001). However, subgroup analysis based on pathological type demonstrated that high SII was an independent predictor for poor OS only in esophageal squamous cell carcinoma (ESCC) patients (HR = 1.72, 95% CI: 1.34–2.21, P < 0.001). Besides, SII was also significantly associated with poor PFS (HR = 1.94, 95% CI: 1.61–2.35, P < 0.001) and CSS (HR = 1.44, 95% CI: 1.04–1.99, P = 0.027) in ESCC patients.

Conclusion

The SII could serve as an independent prognostic factor in surgical ESCC patients and higher SII was related with worse survival. However, more prospective high-quality studies are still needed to verify above findings.