Significance of preoperative fibrinogen levels, neutrophils-tolymphocyte ratio and its combined scores in evaluating the prognosis of postoperative patients with gastric cancer

Jian-Zhong Deng, Xiu-Ling Liu, Qian Liu, Wen-Jing Li, Wen-Bin Lu

Department of Oncology, Wujin Hospital Affiliated to Jiangsu University, Wujin Clinical College of Xuzhou Medical University, Changzhou 213017,China

Keywords:Fibrinogen Neutrophils-to-lymphocyte ratio F-NLR Gastric cancer Prognosis

ABSTRACT Objective:To investigate the clinic significance of the combined detection of peripheral fibrinogen (Fbg) and neutrophils-to-lymphocyte ratio (NLR) (F-NLR) on the prognosis of postoperative gastric cancer patients. Methods: The clinical and pathological characteristics of 70 gastric cancer patients who were diagnosed by gastroscopy and surgically resected were collected, and the relationship between Fbg, NLR and F-NLR scores and pathological characteristics and prognosis of gastric cancer patients was retrospectively analyzed. Results:There were statistically significant differences in the levels of NLR in gastric cancer patients of different genders (P ＜ 0.05), while there were no significant differences in the levels of NLR and Fbg in other pathological factors such as age, T stage, lymph node metastasis and TNM stage(P ＞ 0.05). The f-NLR score of gastric cancer patients with different gender, T stage and TNM stage had statistical significance (P ＜ 0.05), but there was no statistical significance in the F-NLR score of gastric cancer patients with different age and whether lymph node metastasis (P ＞ 0.05). Univariate analysis showed that Fbg, NLR, F-NLR score, and TNM stage had an effect on recurrence and survival of patients with gastric cancer after surgery (P＜0.05); multivariate COX regression analysis showed that only F-NLR score and TNM stage were independent risk factors for relapse and survival of patients with gastric cancer (P ＜0.05).Conclusion: The F-NLR scores about the combined detection of Fbg and NLR may guide clinical prediction of the prognosis of gastric cancer patients.?Corresponding author: LU Wen-bin, Master Supervisor, Chief Physician.LU Wenbin, Master Supervisor, Chief Physician.

1. Introduction

Gastric cancer (GC) ranks second in malignant tumors in my country, and is the most common malignant tumor of the digestive tract; it ranks third in the cause of death from malignant tumors [1].Although there have been great advances in the surgical methods and postoperative treatment of GC, postoperative recurrence or distant metastasis is still the main influencing factor for the poor prognosis of GC patients. Therefore, independent prognostic factors should be determined for GC patients to choose individual Medical treatment is very important [2]. Previous studies have shown that inflammation is closely related to the occurrence and development of tumors. Fibrinogen (Fbg), as a coagulation cascade factor, has been shown to play an important role in systemic inflammation and tumor progression [2, 3]. The neutrophils-to-lymphocyte ratio(NLR) is a major marker of inflammatory response and is related to the poor prognosis of patients with various tumors [4-6]. Studies have shown that combined Fbg and NLR detection indicators(F-NLR) can predict the prognosis of cancer patients [7-9]. This article retrospectively analyzes the relationship between Fbg, NLR and F-NLR scores in the clinical data of GC patients, and aims to explore the significance of F-NLR in evaluating the prognosis of patients with resectable GC.

2. Materials and methods

2.1 Clinical data

We selected 70 GC patients who underwent surgical treatment in our hospital from January 2015 to June 2017, including 53 males and 17 females, aged 28-74 years (median age 62 years). Inclusion criteria: (1) Patients who can be resected by gastroscopy and imaging before surgery, and the pathology after surgery is clearly diagnosed as adenocarcinoma; (2) Patients who have not received neoadjuvant radiotherapy or chemotherapy before surgery. Exclusion criteria:(1) patients with other malignant tumors; (2) patients with acute or chronic infections before surgery; (3) patients with anticoagulation therapy before surgery; (4) perioperative or non-GC related deaths Of patients. The 7th edition of AJCC gastric cancer TNM staging system was used for staging.

1.2 Detection method and grouping

The special vacuum tube for coagulation test (containing sodium citrate anticoagulation) was used to collect 2.5ml of fasting peripheral venous blood of admitted patients within 1 week before the operation, and Fbg detection was performed after the plasma was centrifuged as required; The blood vessel (including EDTAK2 anticoagulation) collects 2.0ml of peripheral venous blood from the patient, uses an automatic blood cell analyzer to test the blood routine, and then calculates the NLR, which is the ratio of neutrophil count/lymphocyte count. The specific detection method and process are consistent with the detection method of our previous published research [10].

2.3 Follow-up

The follow-up time for all patients starts from the day of surgery,mainly by telephone and outpatient follow-up. The deadline for follow-up is June 30, 2019. The main endpoint events are tumor recurrence, metastasis, and tumor-related death. The overall survival(OS) is calculated: from the date of surgery to the date of patient death or the last follow-up; and disease free survival (DFS) ): The date of surgery to the date that imaging or gastroscopy suggests local recurrence, metastasis or death.

2.4 Statistical methods

The SPSS19.0 statistical software was used for analysis, and the count data was expressed as n, and χ2or Fisher's exact test was used for comparison between groups. According to the receiver operating characteristic curve (receiver operating characteristic curve, ROC curve for short), the critical values of Fbg and NLR are calculated and determined. Survival analysis was established by Kaplan-Meier method and Log-rank test. Multivariate analysis was performed using Cox risk regression model. With the two-sided test level=0.05, P＜0.05, the difference is considered to be significant.

3. Results

3.1 Thresholds of Fbg and NLR

The area, specificity, sensitivity, and cut-off value under the Fbg curve calculated using the ROC curve are 0.618, 62.8%, 62.9%, and 2.93g/L, respectively; the area, specificity, sensitivity, and cut-off value under the NLR curve are respectively 0.745, 82.9%, 57.1%and 2.23. The F-NLR scoring grouping standard is: Fbg＞2.93g/L and NLR＞2.23 are defined as F-NLR 1 group; Fbg≤2.93g/L and NLR≤2.23 and Fbg＞2.93g/L or NLR＞2.23 are defined as F-NLR 1.Group F-NLR 0. The ROC curve is shown in Figure 1.

Figure1 ROC curve of Fbg and NLR with the overall survival

3.2 Comparison of Fbg, NLR and F-NLR scores with clinicopathological characteristics of GC patients

The difference in NLR levels in patients with gastric cancer of different genders was statistically significant (P＜0.05), and other different pathological factors such as age, T staging, lymph node metastasis, and TNM staging gastric cancer patients had no significant differences in NLR and Fbg levels (P＞ 0.05); the difference in F-NLR scores of gastric cancer patients with different gender, T stage and TNM stage was statistically significant (P＜0.05),but there was no significant difference in F-NLR scores of different ages and lymph node metastasis (P＞0.05) . See Table 1.

3.3 Relevant single factors affecting the prognosis of GC patients and Cox analysis

Univariate analysis showed that the depth of tumor invasion(T), tumor stage (TNM), Fbg, NLR and F-NLR scores were significantly different from the OS of GC patients (P＜0.05), see Table 2. Multivariate analysis of the above factors using Cox regression model showed that F-NLR and tumor staging (TNM)are independent risk factors that affect the prognosis of GC patients(P＜0.05), see Table 3.

Table 1 Relationship between Fbg、NLR and F-NLR scores with pathological characteristics of GC patients[n(%)]

Table 2 Univariate analysis of prognostic factors affecting OS and DFS

Table 3 Multivariate analysis of prognostic factors affecting OS and DFS

3.4 F-NLR score and survival analysis of GC patients

The median OS and DFS of 70 GC patients were 33.8 months and 28.5 months, respectively. The OS with F-NLR score of 0 and 1 was 35.0 months and 24.0 months, respectively, the difference was statistically significant (p＜0.0001); the DFS with F-NLR score of 0 and 1 was 30.9 months and 13.8 months, respectively, the difference was significant Sex (p＜0.0001), see Figure 2.

Figure 2 Kaplan-Meier survival curves according to the F-NLR score for(A) OS and (B) DFS

4. Discussion

Although important progress has been made in the mechanism,diagnosis, and treatment strategies of the occurrence and development of GC, the OS of patients with resectable advanced GC is still unsatisfactory and needs further improvement [11]. The high postoperative recurrence or metastasis rate of advanced GC patients may be due to the lack of specific prognostic markers, which makes it impossible to adjust the clinical treatment plan of GC patients in time [12]. Although relevant tumor markers such as carcinoembryonic antigen, carbohydrate antigen (CA) 19-9 and CA72-4 have been widely used in clinical practice to evaluate disease diagnosis and prognosis, they are not the most effective due to their limited sensitivity and specificity. Good GC diagnostic and prognostic markers. The AJCC gastric cancer TNM staging system can be used to evaluate the prognosis of patients after GC, but it cannot reflect individual differences. Therefore, it is necessary to explore new prognostic biomarkers of GC.

Our current research results show that: a cumulative score F-NLR constructed by the combined detection of Fbg and NLR is an independent factor predicting the prognosis of GC patients.Moreover, the acquisition of F-NLR indicators is simple, convenient,and economical, which has important clinical significance for the evaluation of the prognosis of GC patients.

Inflammation can increase the risk of developing malignant tumors through oncogene mutations, angiogenesis, and changes in the tumor microenvironment [13]. Systemic inflammation can promote tumor metastasis, microvascular regeneration and tumor cell proliferation[14, 15]. Neutrophils, as a key inflammatory cell type, increase the release of reactive oxygen species that directly damage DNA by up-regulating inducible NO synthase (iNOS), leading to tumor progression [16]. Lymphocytes play an important role in the immune response and are also the main factor in inhibiting cancer progression[17]. NLR is a reliable and accurate marker of inflammation. Previous studies have shown that there is a significant difference in NLR levels between breast invasive ductal carcinoma and non-invasive ductal carcinoma (lobular or mixed) histology. There is no significant difference in the level of NLR in the variables such as age, tumor size, grade and other clinicopathological characteristics [18]; studies have shown that high NLR is considered to be significantly related to the poor survival rate of solid tumors [19, 20]. However, some studies have shown that NLR cannot predict the prognosis of cancer patients [21, 22]. There is no statistically significant difference in Fbg levels in non-small cell lung cancer patients with different genders and ECOG scores [23]. Fbg or NLR alone may have a limited effect on tumor progression. F-NLR reduces the adverse effects of Fbg or NLR alone, and ultimately increases The predictive significance of patients with malignant tumors. Therefore, we explored the F-NLR score to evaluate the prognostic value of GC patients.

Previous related studies have shown that F-NLR is related to T stage, tumor size, neural invasion and mucinous adenocarcinoma,that is, increased F-NLR may be beneficial to tumor proliferation,invasion and metastasis; single-factor and multi-factor analysis show that F- NLR score is an independent risk factor for patients with resectable colorectal cancer [24]. However, the prognostic value of F-NLR score in evaluating GC patients is still unclear.This study aims to explore the clinical significance of F-NLR in the prognosis of patients with resectable GC. Our research results show that the F-NLR score is related to the gender, T staging, and TNM of GC patients, and has nothing to do with age and lymph node metastasis. However, studies have shown that the F-NLR score is related to clinicopathological factors such as gender, age, tumor size,and lymph node metastasis in patients with resectable non-small cell lung cancer [25]. This study further analyzed the relationship between the F-NLR score and the survival prognosis of patients with resectable GC. The results showed that the OS and DFS prolongation of patients with a F-NLR score of 0 were significantly improved compared with that of patients with a score of 1, and the difference in prolonged OS and DFS was statistically significant. Significance,suggesting that GC patients with low F-NLR scores may not be prone to relapse and may obtain a longer OS. COX risk regression model analysis results show that F-NLR and TNM are independent risk factors that affect the prognosis of patients with resectable GC,and suggest that F-NLR score, like tumor TNM, can predict the prognosis of patients with resectable GC.

Based on previous and our research results, the F-NLR score can be suitable as an indicator for predicting the prognosis of cancer patients, but we must acknowledge the limitations of the current study: First, this is a single-center, small-sample retrospective study. There may be a bias that reduces statistical power; second,it should be recognized that fibrinogen, neutrophil and lymphocyte counts are non-specific parameters, because they may be affected by accompanying conditions, and there is no consensus on cut-off values. Therefore, multi-center, large sample and even prospective studies are needed to prove our conclusions.

In summary, this study analyzed the relationship between the F-NLR score based on inflammatory cells and coagulation factors and the clinicopathological factors of GC patients, and also explored the relationship between the F-NLR score and the prognosis of GC patients. The results suggest that the F-NLR score affects GC The patient's independent prognostic factor is a reliable indicator that is expected to guide clinical prediction of the prognosis of patients with resectable GC.

Author’s contribution

Deng Jianzhong: project design, data sorting, statistical analysis and writing papers; Lu Wenbin: project design and proofreading;Liu Xiuling, Li Wenjing: data receipt, case follow-up; Liu Qian: data sorting and guiding statistical analysis. All authors have read and approved this manuscript.