Ze-Yun Li, Qing-Xia Lan, Cheng-Xin Liu, Zhe Sun, Yang Cao

1. First College of Clinical Medicine,Guangzhou University of TCM,Guangzhou 510405,China

2. Department of Oncology,the First Affiliated Hospital of Guangzhou University of TCM,Guangzhou 510405,China

ABSTRACT Objective: To systematically evaluate the efficacy and safety of rh-endostain(YH-16,Endostar)combined with vinorelbine and cisplatin (NP regimen) in the treatment of non-small cell lung cancer(NSCLC),and to provide evidence-based reference for clinical drug use. Methods:Retrieved from PubMed, EMBASE, the Cochrane Library, Clinical Trials, CNKI, VIP and Wan Fang database, randomized controlled trials(RCT)about YH-16 combined with NP regimen(NPY regimen, trial group) vs. NP regimen(control group)for NSCLC were collected.After screening the literature and extracting the data, the two persons evaluated the quality of the included studies, and used Rev Man 5.3 software to merge effect size. Results: A total of 18 articles were included, with a total of 2051 patients. Results of Meta-analysis showed that response rate [RR＝1.66,95%CI(1.44,1.91),P＜0.00001]、 clinical benefit rate [RR＝1.21,95%CI(1.14,1.29),P＜0.00001] and quality of life improvement rate [RR＝3.42,95%CI(2.45, 4.79),P＜0.00001] of trial group were significantly higher than those of control group.Besides, the serum CEA level [MD＝-4.78,95%CI(-7.11,-2.46),P＜0.0001] and CA125 level [MD＝-16.44,95%CI(-20.83,-12.05),P＜0.00001] of trial group were significantly lower than that of control group. There was no statistical significance in the 1-year survival rate and the incidence of myelosuppression, cardiotoxicity, gastrointestinal reaction, damage to the kidneys and liver, and alopecia (P＞0.05). Conclusion: Compared with NP regimen alone, NPY regimen can improve the efficacy and quality of life of NSCLC patients, reduce the level of tumor markers, and does not increase the occurrence of adverse reactions, and has good efficacy and safety. However, the existing evidence shows that NPY regimen has the same effect as NP regimen alone in improving the 1-year survival rate of patients. The above conclusions need to be confirmed by further studies.

Keywords:Rh-endostain Vinorelbine Cisplatin Non-small cell lung cancer Therapeutic efficacy Safety Meta-analysis

1. Introduction

The incidence of lung cancer (11.6%) ranks first in malignant tumors, and its mortality rate (18.4%) is also the highest in the global mortality rate of malignant tumors, and the incidence and mortality rates are still on the rise [1]. Lung cancer is mainly nonsmall cell lung cancer(NSCLC), accounting for more than 80%.Due to the limitations of screening technology, early diagnosis is often difficult. Studies have shown that 60% to 70% of NSCLC are already at an advanced stage when they are diagnosed [2].Surgical treatment and other treatment methods are greatly restricted. Therefore, the treatment of advanced NSCLC is mainly a comprehensive treatment based on chemotherapy. However, due to the characteristics of large lesions and prone to metastasis, the efficacy of treatment based on chemotherapy alone has not been achieved [3].

With the in-depth research on the pathogenesis of lung cancer, it has been discovered that abnormal blood vessel proliferation is a key step for tumor cell survival, growth and spread [4]. Therefore,anti-angiogenesis therapy has become a hot topic in modern tumor research. Endostar (recombinant human endostatin, YH-16), an anti-tumor angiogenesis drug, is a more stable, more effective and longer effective product based on endostatin molecule developed by Chinese scientist Luo Yongzhang [5]. At present, a number of clinical studies have confirmed that YH-16 combined with vinorelbine and cisplatin (NP regimen) can significantly improve the objective curative effect in the treatment of NSCLC, and does not increase the adverse reactions of chemotherapy [6]. However, many studies have shortcomings such as small sample size and low quality. Therefore,in order to clarify the extent to which the combination of Endo,vinorelbine, and cisplatin (NPY regimen) benefit NSCLC patients,meta-analysis of existing research results is needed. Method of systematic and quantitative comprehensive analysis, and follow the PRISMA guidelines for reporting, in order to obtain a more reliable evidence-based basis [7].

2. Materials and methods

2.1 Acceptance criteria

2.1.1 Research type

Randomized controlled trial (RCT)

2.1.2 Research objects

Patients need to meet the histological/cytopathological diagnostic criteria of NSCLC, regardless of race, age, sex, and course of disease.

2.1.3 Intervention measures

Patients in the control group were treated with NP chemotherapy;patients in the experimental group were treated with NPY chemotherapy. There is no limit to the dosage, duration of treatment,etc.

2.1.4 Outcome measures

Short-term effects: ①effective rate, ②clinical benefit rate; tumor marker level: ③serum CEA level, ④CA125 level; quality of life improvement rate; 1-year survival rate; main adverse reactions:decreased platelets, decreased white blood cells, decreased hemoglobin, cardiotoxicity, gastrointestinal reactions, hair loss, liver and kidney damage, etc.

2.1.5 Exclusion criteria

①Jadad scale score is 0; ②Animal experiments; ③Retrospective studies; ④Non-Chinese and English literature; ⑤Repeated publications; ⑥Studies that do not include the above outcome indicators.

2.2 Literature search strategy

Search PubMed, EMBASE, the Cochrane Library, Clinical Trials,CNKI, VIP and Wan Fang databases. The search terms are "YH-16", "Rh-endostatin", "Recombinant human endostatin injection","Endostatin", "NP Regimen", "vinorelbine", "Cisplatin", "Non-small cell lung cancer", "NSCLC" etc. YH-16 came out in 1999 [8], the search time limit is from 1998 to June 2020.

2.3 Literature screening and data extraction

Two researchers (Li Zeyun, Lan Qingxia) independently screened the literature according to the inclusion criteria, extracted data,and cross-checked. If there is a dispute, the third researcher (Liu Chengxin) will assist in the planting. The extracted content includes①Basic information: author, publication year, sample size of each group, age, course of treatment, pathological stage; ②Two intervention measures, including dosage, frequency of use, method of administration, time of medication, etc.; ③Outcome indicators,etc.

2.4 Literature quality evaluation

The literature quality evaluation was completed independently by two persons and cross-checked. The risk of bias included in the RCT is assessed according to the Cochrane Manual 5.1.0 Risk of Bias Assessment Tool. The quality of the included studies was evaluated using the improved Jadad scale, with a total score of 1 to 7, with a score of 3 or less as low quality, and a score of 4 or more as high quality [9].

2.5 Statistical methods

RevMan 5.3 software was used for data analysis. The count data used risk ratio (RR) and its 95% confidence interval (CI) as the effect size, and the measurement data used the mean difference(MD) and its 95% CI as the effect size. Different models are used for analysis. If the conditions of P≥0.1 and I2≤50% are met, there is no statistical heterogeneity, and the fixed-effects model is used for analysis; otherwise, the random-effects model is used. In order to evaluate the reliability and stability of the results, a sensitivity analysis method is adopted. For analysis of potential publication bias, an inverted funnel chart and Stata12.0 software were used to perform Begg’s and Egger’s tests on the included studies. P＜0.05 indicates that the difference is statistically significant.

3. Results

3.1 Literature search results

Screened layer by layer according to the inclusion criteria,and finally included a total of 18 articles [10-27], a total of 2051 patients, as shown in Figure 1. Among them, there are 14 Chinese documents [10-23] and 4 English documents [24-27];the Jadad scores of 9 studies [10, 12-16, 21, 23, 25] are high-quality studies, and 9 [11, 17-20, 22, 24, 26, 27] are low-quality studies.

Figure 1 Literature screening process

3.2 The quality evaluation results of the included studies

The quality evaluation results are shown in Figure 2 and Figure 3.Seven studies [10, 12-16, 23] reported random methods; 6 studies [13,14, 16, 17, 23, 26] resulted in incomplete data; 2 Studies [13, 14, 16, 17,23, 26] reported allocation concealment; 2 studies [15, 25] mentioned blinding; 18 studies had no record of describing other sources of bias.

Figure 2 Bar graph of bias risk

Figure 3 Bias risk graph

3.3 Meta analysis results

3.3.1 Response rate

Seventeen studies [10-26] reported the response rate, and there was no statistical heterogeneity among the studies (P=0.91, I2=0%),and the fixed effects model was used for analysis. The results showed that compared with the control group, the NPY regimen can increase the response rate by 1.66 times, and the difference is statistically significant [RR=1.66, 95%CI (1.44, 1.91), P＜0.00001].It is suggested that the synergy between the NPY regimen can significantly improve the clinical efficacy than the NP regimen alone(Fig 4).

Figure 4 Forest plot of Meta-analysis of response rate in 2 groups

3.3.2 Clinical benefit rate

Seventeen studies [10-26] reported the clinical benefit rate, and there was no statistical heterogeneity among the studies (P=0.52, I2=0%),and the fixed effects model was used for analysis. The results show that compared with the control group, the NPY regimen can increase the clinical benefit rate by 1.21 times, and the difference is statistically significant [RR=1.21, 95%CI (1.14, 1.29), P＜0.00001]. It is suggested that the synergy between NPY regimen can effectively control the disease progression of patients than using NP regimen alone (Fig 5).

Figure 5 Forest plot of Meta-analysis of clinical benefit rate in 2 groups

3.3.3 Serum tumor marker levels

Three studies [10, 14, 23] reported serum CEA levels, and there was statistical heterogeneity among the studies (P＜0.0001, I2=91%),using random effects model analysis (Fig 6); 2 studies [10, 25] reported serum CA125 levels, and there was no statistical heterogeneity among the studies (P=0.65, I2=0%), using a fixed-effects model analysis, see Figure 6B for details. The results showed that serum CEA and CA125 levels in the test group were significantly lower than those in the control group, and the difference was statistically significant [MD=-4.78, 95% CI (-7.11, -2.46), P＜0.0001; MD=-16.44, 95 %CI (-20.83, -12.05), P＜0.00001]. It is suggested that the NPY regimen can reduce the serum CEA and CA125 levels in NSCLC patients, and help retard the progression of the patient's condition.

Figure 6 Forest plot of Meta-analysis of serum tumor marker levels in 2 groups

3.3.4 Quality of life improvement rate

Two studies [13, 18] reported the improvement rate of quality of life, and there was no statistical heterogeneity between the studies(P=0.79, I2=0%), and the fixed effects model was used for analysis.The results showed that compared with the control group, the NPY regimen can increase the quality of life improvement rate by 3.42 times, and the difference is statistically significant [RR = 3.42, 95%CI (2.45, 4.79), P ＜0.00001] (Fig 7).

Figure 7 Forest plot of Meta-analysis of quality of life improvement rate in 2 groups

3.3.5 1-year survival rate

Two studies [16, 18] reported the 1-year survival rate, and there was statistical heterogeneity between the studies (P=0.07, I2=70%), and random effects model analysis was used. The results showed that compared with the control group, the NPY regimen can improve the 1-year survival rate, but the difference was not statistically significant[RR = 2.60, 95% CI (0.90, 7.57), P = 0.08] (Fig 8).

Figure 8 Forest plot of Meta-analysis of 1-year survival rate in 2 groups

3.3.6 Incidence of major adverse reactions

The main adverse reactions such as thrombocytopenia, white blood cell decline, hemoglobin decline, cardiotoxicity, gastrointestinal reactions, hair loss, liver and kidney function damage were analyzed by meta-analysis, and the results are summarized in Tab 1. The results showed that the incidence of platelet decline, white blood cell decline, gastrointestinal reactions, hair loss, and liver and kidney damage in the experimental group was lower than that of the control group (RR＜1), while the incidence of hemoglobin decline and cardiotoxicity in the experimental group was higher than that of the control group (RR＞1), but the difference between the two groups was not statistically significant (all P＞0.05).

Table1 Summary of the incidence of major adverse reactions

3.4 Sensitivity analysis

The response rate is used as an indicator for sensitivity analysis.After removing any of the studies one by one, the results of the meta-analysis are basically consistent with the previous results,indicating that the results of this study are reliable and the strength of the argument is high (Tab 2).

Table 2 Results of sensitivity analysis

3.5 Analysis of publication bias

For 17 studies on reporting response rate, the inverted funnel plot,Begg’s test and Egger’s test were used for publication bias analysis.The scattered points of the studies in the inverted funnel chart are all within the 95% CI line, with good symmetry, indicating that this study has no obvious publication bias. The P value of Begg’s test is 0.323＞0.05, and the P value of Egger’s test is 0.366＞0.05, both of which indicate that the publication bias of the literature included in this study is small(Fig 9～11).

Figure 9 Funnel plot of response rate

Figure 10 Begg’s analysis plot of response rate

Figure 11 Egger’s analysis plot of response rate

4. Discussion

Cisplatin has a killing effect on tumor cells of all stages. It mediates tumor cell apoptosis or necrosis mainly through binding to tumor cell DNA. It is a cell cycle non-specific drug and is a first-line drug for advanced lung cancer. Advantages such as good curative effect,broad anti-tumor spectrum, and mild bone marrow suppression [28].Vinorelbine's anti-cancer mechanism is to prevent the polymerization of tubulin and then affect the formation of the spindle, so that cell proliferation stops at the metaphase of mitosis [29]. The combination of the two can improve the objective remission rate and patient survival rate of NSCLC, and is one of the preferred medication regimens for NSCLC [30]. However, studies have shown [10] that this program has limited efficacy and has not yet achieved satisfactory results for improving the condition of advanced patients. The above shows that the chemotherapy of NSCLC has reached a bottleneck period, and it is particularly urgent to find a new treatment plan to replace or supplement traditional chemotherapy.

According to the viewpoint put forward by Folkman [31], antitumor angiogenesis therapy can effectively inhibit the growth and metastasis of malignant tumors. YH-16 can exert anti-angiogenic activity by inhibiting the phosphorylation process of nucleolar protein, and inhibit all links of the tumor angiogenesis process.Compared with bevacizumab, its use is not easy to be restricted and belongs to a kind of Multi-target anticancer drugs [32]. In addition to blocking the growth and migration of vascular endothelial cells and inducing their apoptosis, it can also change the permeability of tumor blood vessels and then improve the tumor microenvironment,and can inhibit endothelial growth factor and its receptors. Cyclin D1, integrins, metalloproteinases, etc. also have a certain degree of inhibition, and can block the Wnt signaling pathway [33, 34].However, YH-16 does not directly act on cancer cells, so the effective rate is very limited. Clinically, combined chemotherapy is still needed. Multiple mechanisms of action kill tumor cells to play a synergistic effect, so as to give full play to their respective advantages and obtain the greatest therapeutic effect.

This Meta analysis shows that the NPY regimen has a good effect,indicating that the combination of anti-angiogenesis therapy on the basis of chemotherapy can not only give full play to the direct therapeutic effect of chemotherapy drugs on tumors, but also block the tumor growth and supply system. The two are organic Combination, complementary advantages, and multi-mechanism synergistic effect, further reduce the level of serum tumor markers and retard the progression of the patient’s condition; another study also shows [35] that for some patients with stage IIIA lung cancer,the combined use can reduce the clinical stage of the tumor and improve Resection rate. In addition, the quality of life of patients is significantly improved, which can improve patient compliance,thereby ensuring the smooth progress of treatment. Based on the above results, despite the existing evidence that the NPY regimen has the same effect as the NP regimen alone in improving the 1-year survival rate of patients, the latest guidelines still use the NPY regimen as a driver gene negative, PS 0-1 advanced NSCLC Category 2B recommendations for first-line treatment of patients[36]. The difference in the results of this study is likely to be related to the small number of study populations (81 cases). Therefore, its long-term efficacy still needs to be further studied to obtain more reliable evidence-based evidence. The results of statistical analysis show that compared with the control group, the NPY regimen does not increase the incidence of adverse reactions in NSCLC patients,indicating that YH-16, as an anticancer drug, has relatively low toxic and side effects and is safer. And research shows that it can even play a certain degree of attenuation, indicating that the combination of multi-mechanism anticancer drugs can indeed not only improve the efficacy, but also improve the quality of life of patients to a certain extent. However, the mechanism of drug interaction still needs further study. When YH-16 is used clinically, it is still necessary to pay attention to related adverse events, especially cardiotoxicity and liver and kidney damage. Corresponding organ function evaluation and targeted prevention should be carried out before use. The results of sensitivity analysis and publication bias analysis indicate that the results of this study are stable and reliable. In a metaanalysis reported by Wang J et al. [37], it was also confirmed that the combination of anti-angiogenic drugs and chemotherapy (NP/TP/DP/GP regimen) can increase the effective rate without increasing the risk of serious adverse events. In summary, the NP program combined with YH-16's multi-channel and multi-mechanism synergistic anti-cancer comprehensive treatment has good efficacy and safety.

The limitations and shortcomings of this study are as follows:1) literature was retrieved from various databases, but the latest clinical trials or grey literatures were not included; 2) Endostar is a domestic drug, and the included study population is mostly Chinese,so the research results are limited in popularization; 3) the quality of included studies varies. Therefore, the above conclusions still need to be confirmed by further research. In view of the fact that most of the clinical trials of NSCLC do not have high requirements for blind method, the main indicators of quality of life and other indicators of patients are not described much, and the follow-up records are few, it is suggested that the research methodology should be further improved, such as adopting multi center, completely randomized research method, setting up allocation concealment or implementing blind method, and improving the follow-up to obtain high-quality research results Research Report.

Author’s contribution

Li Zeyun, the first author, is responsible for the design and writing of the paper, completing the literature screening and data extraction; Lan Qingxia and Li Zeyun are responsible for the independent cross screening of literature and data extraction, Liu Chengxin is responsible for the verification and consultation, and assisting in the revision of the article and related chart formats; Zhe sun is responsible for the revision of the paper, and Cao Yang, the corresponding author, is responsible for the topic selection, design and revision. Thanks.