Is Huachansu Beneficial in Treating Advanced Non-Small-Cell Lung Cancer? Evidence from a Meta-Analysis of Its Efficacy Combined with Chemotherapy

Background. Huachansu, the sterilized water extract of Bufo bufo gargarizans toad skin, is used in China to alleviate the side-effects and enhance the therapeutic effect of chemotherapy in advanced non-small-cell lung cancer (NSCLC). We conducted a meta-analysis to assess Huachansu's efficacy. Methods. We extensively searched electronic databases (CENTRAL, EMBASE, MEDLINE, CBM, Cochrane Library, CNKI, CEBM, WFDP, CSCD, CSTD, and IPA) for randomized controlled trials containing Huachansu plus chemotherapy as the test group and chemotherapy as the control group. Seventeen trials were selected based on the selection criteria. The pooled relative ratio (RR) of indicators with 95% confidence interval (95% CI) was calculated for efficacy evaluation. Results. The meta-analysis demonstrated a statistically significant improvement in objective tumor response, one-year survival, Karnofsky performance status, pain relief, and alleviation of severe side-effects (nausea and vomiting, leukocytopenia) in the test group as compared to the control group, but no significant difference in thrombocytopenia. Conclusions. This study demonstrated the efficacy of Huachansu combined with chemotherapy in the treatment of advanced NSCLC. However, limitations exist and high-quality trials are needed for further verification.


Introduction
Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer, which is difficult to diagnose in early stages. Patients diagnosed with advanced NSCLC are often unable to undergo surgery, thus reducing the survival time [1]. So far, chemotherapy is typically used for the treatment of advanced NSCLC. However, chemotherapy not only kills tumor cells but also causes several side-effects. Many patients have to endure great discomfort to prolong their lives for a limited time. So providing efficacious therapy while improving the patient's quality of life is the primary concern of clinicians when selecting appropriate regimens. Evidence-Based Complementary and Alternative Medicine of traditional Chinese medicine (TCM) [7,8]. The Chinese Food and Drug Administration approved Huachansu in 1991 for the treatment of chronic HBV infection and cancers (predominantly as standard-of-care monotherapy for pancreatic and hepatobiliary malignancies) [9].
In order to alleviate the side-effects of chemotherapy and enhance therapeutic efficacy in advanced NSCLC, several clinical studies have been conducted using Huachansu combined with chemotherapy to observe whether this would be beneficial for patients. But due to the limited scale of these studies, certain results remain inconsistent. Therefore, we performed a meta-analysis by pooling the randomized clinical trials to evaluate the efficacy of this complementary therapy. The retrieval terms used were as follows: (non-small-cell lung cancer OR non-small-cell lung carcinoma OR NSCLC OR squamous cell lung carcinoma OR large cell lung carcinoma OR lung adenocarcinoma) AND (Huachansu OR Hua chan su OR Cinobufacini).

Study Selection.
Studies that met the following criteria were included: (1) type of studies: clinical randomized controlled trials (RCTs); (2) participants: age ≥18 years with pathology and CT diagnosis of NSCLC in stage III or IV with detectable solid tumor and KPS ≥60; (3) type of intervention: treatment with Huachansu combined with chemotherapy as the test group; (4) type of outcome: reports with at least one of the following indicators: objective tumor response, one-year survival, quality of life (KPS scale), pain relief, major drug adverse reactions, or the data necessary to calculate them. Clinical trials were excluded if they did not meet the above criteria. The following types of studies were also excluded: (1) treatment without chemotherapy as the control group; (2) nonoriginal or duplicated publications; (3) patients with other serious illnesses.

Quality Assessment and Data Extraction.
All reports were independently reviewed by two reviewers (BD Zhou and FY Wu) to evaluate their quality, decide which study would meet the eligibility criteria, and extract the data needed: author names, year of publication, study type, patient information, details of the treatment, and outcome. Any disagreements were resolved through discussion or by a third reviewer.

Meta-Analysis.
The STATA (version 11.0) was used for data analysis. Relative ratio (RR) and 95% confidence intervals (CI) were calculated. < 0.05 was considered to be statistically significant. To determine whether the randomeffects or fixed-effects model should be used, the 2 was used to estimate heterogeneity (random-effects model when 2 ≥ 50% or fixed-effects model when 2 < 50%) [27].

Description of Enrolled Studies.
In this study, seventeen trials were selected based on selection criteria. A total of 80 publications were originally identified, of which 63 studies were excluded and 17 studies were finally included based on the selection criteria with 1142 enrolled patients (578 in the test group and 564 in the control group) [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The selection process and reasons for exclusion are described in Figure 1, and the characteristics of the included studies are presented in Table 1.
All 17 studies mentioned random allocation, but only six studies described random allocation methods. No study described the blind method and allocation concealment. All patients recruited in these studies were diagnosed at stages III to IV NSCLC TNM. These patients were given an overall physical assessment before treatment, including age, quality of life score, and stage of disease. No significant differences between the baseline data were reported and all patients were estimated with life expectancy ≥3 months. Different combination chemotherapies were used for treatment: vinorelbine plus cisplatin (NP), docetaxel plus cisplatin (DC), paclitaxel plus cisplatin (TP), gemcitabine plus cisplatin (GP), etoposide plus cisplatin (EP), vinorelbine plus carboplatin (NC), vinorelbine plus ifosfamide (NI), and pemetrexed plus cisplatin. The methodological quality was evaluated using the Jadad scale according to the description in these reports on randomization, blinding method, withdrawals/dropouts, and allocation concealment, which was presented in Table 2.

Objective Tumor Response Results.
Thirteen trials reported the number of treated patients with complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) in each group, based on the WHO scale. The objective tumor response was determined by the number of patients with CR plus PR. Meta-analysis showed a significant increase in the number of patients with CR plus PR in the Huachansu plus chemotherapy test group (RR = 1.379, 95% CI, 1.190-1.599, < 0.0001, 879 patients). A fixed-effects model was used since heterogeneity was absent ( 2 = 0%, = 0.989) ( Figure 2).      Evidence-Based Complementary and Alternative Medicine     patients surviving > one year in the test group as compared to the control group (RR = 1.316, 95% CI, 1.077-1.607, = 0.007, 262 patients). As heterogeneity was absent ( 2 = 0%, = 0.749), a fixed-effects model was used (Figure 3). Since heterogeneity was absent ( 2 = 0%, = 0.755), a fixedeffects model was used (Figure 4).

Pain Relieving Effects.
Four trials reported the number of patients with pain relief after treatment. The degree of pain was assessed with the WHO rating scale. Meta-analysis showed a significant increase in the number of patients with complete plus partial pain relief in the test group (RR = 1.64, 95% CI, 1.293-2.080, < 0.0001, 296 patients). Since heterogeneity was absent ( 2 = 0%, = 0.757), a fixed-effects model was used ( Figure 5).   374 patients). As heterogeneity was absent ( 2 = 0%, = 0.970), a fixed-effects model was used (Figure 8).

Sensitivity Analysis
Results. The fixed-effects and random-effects models were used to perform sensitivity analysis. Though the value increased for certain indicators when using the random-effects model, the outcomes did not change. The results are displayed in Table 3.

Publication Bias Analysis.
Begg's funnel plot and Egger's linear regression test were used to evaluate the publication bias. The result of Egger's test suggested a publication bias among the studies within the group of thrombocytopenia ( = 0.036). No bias was observed in the other groups. The results are displayed in Figure 9 and Table 4.

Discussion
So far Huachansu has been used mainly in China, and most of the clinical trials were performed by separate hospitals with a small sample size. The number of patients included in most trials was < 100. So certain results were not very convincing. For example, five studies claimed no statistically significant improvement in the objective tumor response in the test group. A meta-analysis offered the unique advantage of merging all these outcomes to get a more comprehensive and accurate evaluation of such complementary therapy.
This meta-analysis showed that Huachansu can increase the objective tumor response and one-year survival, improve performance status, alleviate severe chemotherapy sideeffects, and relieve cancer pain, which may be attributed to the various ingredients in Huachansu, which is just like a troop equipped with multiple weapons. So far, more than 30 ingredients have been identified in the skin secretion of Bufo bufo gargarizans and the major functional ingredients include cardiac glycosides (Cinobufagin, Resibufogenin, Bufalin, etc.) and indole alkaloids (Bufotenine, Cinobufotenine, Serotonin, etc.). Experiments have shown that Cinobufagin, Resibufogenin, and Bufalin strongly inhibit tumor cells, and Bufotenine, Cinobufotenine, and Serotonin can act on the neural system [5,28]. Therefore, the clinical effects of Huachansu correspond well with the physiological activities of these ingredients.

Conclusions
In summary, this meta-analysis suggests that Huachansu, as a natural medicine containing many active ingredients, can be a promising supplement to routine chemotherapy in treating advanced NSCLC. However a major limitation of this study is the low methodological quality of the included reports. Therefore, more high-quality trials are needed in the future to validate these findings. Besides, to avoid publication bias, the likelihood of publication of trials should in no way depend on whether the results were positive or negative.