Nomogram based on tumor-associated neutrophil-to-lymphocyte ratio to predict survival of patients with gastric neuroendocrine neoplasms

Abstract

Aim: To assess the predictive value of the tumor-associated neutrophil-to-lymphocyte ratio in terms of the clinical outcomes of patients with gastric neuroendocrine neoplasms after radical surgery.

Methods: Data were retrospectively collected from 142 patients who were diagnosed with gastric neuroendocrine neoplasms and who underwent radical gastrectomy at our department from March 2006 to March 2015. These data were retrospectively analyzed, and a receiver operating characteristic curve analysis was used to identify the optimal value of the tumor-associated neutrophil-to-lymphocyte ratio. Univariate and multivariate survival analyses were used to identify prognostic factors. A nomogram was then applied to predict clinical outcomes after surgery.

Results: The tumor-associated neutrophil-to-lymphocyte ratio was significantly associated with tumor recurrence, especially with liver metastasis and lymph node metastasis (P < 0.05 for both), but not with clinical characteristics (P > 0.05 for all). A multivariate Cox regression analysis identified the tumor-associated neutrophil-to-lymphocyte ratio as an independent prognostic factor for recurrence-free survival and overall survival (P < 0.05 for both). The concordance index of the nomograms, which included the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio, was 0.788 (0.759) for recurrence-free survival (overall survival) and was higher than the concordance index of the traditional TNM staging system [0.672 (0.663)].

Conclusion: The tumor-associated neutrophil-to-lymphocyte ratio is an independent prognostic factor in patients with gastric neuroendocrine neoplasms. Nomograms that include the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio have a superior ability to predict clinical outcomes of postoperative patients.

Keywords: Gastric neuroendocrine neoplasms; Prognosis; Tumor recurrence; Tumor-associated neutrophil-to-lymphocyte ratio.

Figure 1

Relationship between the tumor-associated neutrophil-to-lymphocyte ratio and tumor recurrence. A: Representative immunohistochemical staining for CD15 (left) and CD8 (right); B: Significant differences in the TA-NLR were observed between the recurrence group (0.46% ± 0.05%, mean ± SE) and the non-recurrence group (0.24% ± 0.03%, P < 0.001). TA-NLR: Tumor-associated neutrophil-to-lymphocyte ratio.

Figure 2

Forest plot showing the hazard ratios (oblongs) and 95%CIs (bars) for RFS (left) and OS (right) (according to subgroups) among 142 patients with gastric neuroendocrine neoplasms undergoing radical surgery. Long-term survival, including RFS and OS, was better among patients with a low TA-NLR than in patients with a high TA-NLR. g-NENs: Gastric neuroendocrine neoplasms. RFS: Recurrence-free survival; OS: Overall survival; TA-NLR: Tumor-associated neutrophil-to-lymphocyte ratio.

Figure 3

Nomograms for the prediction of recurrence-free survival (A) and overall survival (B) in patients following gastric neuroendocrine neoplasm resection; the C-index was 0.788 and 0.759 for RFS and OS, respectively. LNR: Lymph node ratio; TA-NLR: Tumor-associated neutrophil-to-lymphocyte ratio.

Figure 4

Survival curves for recurrence-free survival (A) and overall survival (B) according to the traditional TNM staging system (NCCN 2015); the C-index was 0.673 and 0.662 for RFS and OS, respectively.