Clinical efficacy and survival analysis of apatinib combined with docetaxel in advanced esophageal cancer

Drug Delivery Opportunities in Esophageal Cancer: Current Treatments and Future Prospects

With one of the highest mortality rates of all malignancies, the 5-year survival rate for esophageal cancer is under 20%. Depending on the stage and extent of the disease, the current standard of care treatment paradigm includes chemotherapy or chemoradiotherapy followed by surgical esophagogastrectomy, with consideration for adjuvant immunotherapy for residual disease. This regimen has high morbidity, due to anatomic changes inherent in surgery, the acuity of surgical complications, and off-target effects of systemic chemotherapy and immunotherapy. We begin with a review of current treatments, then discuss new and emerging targets for therapies and advanced drug delivery systems. Recent and ongoing preclinical and early clinical studies are evaluating traditional tumor targets (e.g., human epidermal growth factor receptor 2), as well as promising new targets such as Yes-associated protein 1 or mammalian target of rapamycin to develop new treatments for this disease. Due the function and location of the esophagus, opportunities also exist to pair these treatments with a drug delivery strategy to increase tumor targeting, bioavailability, and intratumor concentrations, with the two most common delivery platforms being stents and nanoparticles. Finally, early results with antibody drug conjugates and chimeric antigenic receptor T cells show promise as upcoming therapies. This review discusses these innovations in therapeutics and drug delivery in the context of their successes and failures, with the goal of identifying those solutions that demonstrate the most promise to shift the paradigm in treating this deadly disease.

Advances in the Theranostics of Oesophageal Squamous Carcinoma

Oesophageal squamous carcinoma (ESCC) is one of the most lethal human malignancies, and it is a more aggressive form of oesophageal cancer (EC) that comprises over 90% of all EC cases in China compared with oesophageal adenocarcinoma (EAC). The high mortality of ESCC is attributed to the late‐stage diagnosis, chemoradiotherapy resistance, and lack of appropriate therapeutic targets and corresponding therapeutic formulations. Recently, emerging clinical and translational investigations have involved genome analyses, diagnostic biomarkers, and targeted therapy for ESCC, and these studies provide a new horizon for improving the clinical outcomes of patients with ESCC. Here, the latest research advances in the theranostics of ESCC are reviewed and the unique features of ESCC (including differences from EAC, genomic alterations, and microbe infections), tissue and circulating biomarkers, chemoradiotherapy resistance, clinical targeted therapy for ESCC, identification of novel therapeutic targets, and designation of nanotherapeutic systems for ESCC are particularly focused on. Finally, the perspectives for future clinical and translational theranostic research of ESCC are discussed and the obstacles that must be overcome in ESCC theranostics are described.

Apatinib inhibits tumour progression and promotes antitumour efficacy of cytotoxic drugs in oesophageal squamous cell carcinoma

Apatinib, a highly selective inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2), inhibits the angiogenesis of tumours. The function and mechanism of apatinib in oesophageal squamous cell carcinoma (ESCC) remain unknown. In present study, we found that the development of ESCC in patients was controlled by treatment of combination of apatinib and a chemotherapeutic drug. Moreover, apatinib efficiently promotes cell apoptosis, inhibits cell proliferation, invasion, epithelial-mesenchymal transition (EMT) and activity of the Akt/mTOR pathway in ESCC cells. Western blot analysis showed that apatinib significantly increased vimentin protein levels, decreased Bcl2, matrix metalloproteinase 9 (MMP9), E-cadherin, p-Akt and p-mTOR protein levels in ESCC cells. Furthermore, apatinib enhanced chemosensitivity of cytotoxic drugs paclitaxel (TAX), 5-fluorouracil (5-FU) and cisplatin (DDP) by upregulating expression of vimentin protein, and downregulating expression of Bcl2, MMP9 and E-cadherin protein in vitro. Compared with single-agent groups, the combination of apatinib with each chemotherapeutic drug significantly repressed tumour growth and angiogenesis through blocking the expression of Ki67 and VEGFR-2 in vivo. Taken together, apatinib efficiently inhibits cell growth through blocking Bcl2 and Akt/mTOR pathway, and suppresses metastasis via inhibiting MMP9 and EMT in ESCC cells. Apatinib promoted antitumour effect of chemotherapeutic agents through promoting cell apoptosis and inhibiting EMT and angiogenesis in ESCC.

Prognostic Significance of Platelet (PLT) and Platelet to Mean Platelet Volume (PLT/MPV) Ratio During Apatinib Second-Line or Late-Line Treatment in Advanced Esophageal Squamous Cell Carcinoma Patients

Background: Apatinib has a certain efficacy for advanced esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the prognostic significance of platelet (PLT) and platelet to mean platelet volume (PLT/MPV) ratio for advanced ESCC patients with apatinib second-line or late-line treatment. Methods: A retrospective study included 80 patients with advanced ESCC who received Apatinib ≥ 2 lines targeted therapy. We collected baseline clinical characteristics and blood parameters from the patients. Kaplan-Meier plots and univariate and multivariate analysis were used to find the factors related to progression-free survival (PFS). Results: The optimal cut-off values of PLT and PLT/MPV ratio were determined by X-tile software. Kaplan-Meier analysis demonstrated that patients in the high PLT group had better PFS than those in the low PLT group (156 d vs 80 d, P <.001), and patients in the high PLT/MPV ratio group had better PFS than those in low PLT/MPV ratio group (157 d vs 85 d, P <.001). Univariate analysis revealed pretreatment PLT and PLT/MPV ratio were significantly correlated with PFS. Multivariate analysis revealed high levels of pretreatment PLT/MPV ratio was an independent predictor of longer PFS (HR: 0.257, 95% CI: 0.089-0.743, P = .012). Conclusion: High levels of baseline PLT and PLT/MPV may indicate a better prognosis in apatinib ≥ 2 lines treatment for advanced ESCC patients.

Apatinib Combined with Paclitaxel and Cisplatin Neoadjuvant Chemotherapy for Locally Advanced Esophageal Squamous Cell Carcinoma

Background: We conducted a trial to evaluate the efficacy and safety of apatinib, a tyrosine inhibitor against vascular endothelial growth factor receptor 2, combined with neoadjuvant chemotherapy in patients with locally advanced esophageal squamous cell carcinoma (ESCC). Materials and Methods: One hundred twenty six patients were randomized into two cycles of paclitaxel and cisplatin (TP) (n = 61) or combined with apatinib (Apa+TP) (n = 65), followed by surgery. The primary endpoint was objective response rate (ORR). Secondary endpoints included pathological complete response (pCR), safety, R0 resection rate, and operative complication rates. Results: Compared with TP chemotherapy alone, adding apatinib to neoadjuvant treatment significantly increased ORR (Apa+TP: 80.0% vs. TP: 54.1%, respectively; p = 0.004). Apa+TP achieved higher pCR rate compared with TP alone (15.4% vs. 4.92%, respectively; p = 0.101). Similar incidences of toxic effects were found between those two groups. No grade 3 or 4 adverse events (AEs) were observed. Meanwhile, apatinib-related AEs, including hypertension, proteinuria, and hand-and-foot syndrome, were mild. The R0 resection rate was 100% in both groups. No significant differences in operation time, intraoperative bleeding, and postoperative complications were observed, and no serious complications occurred. Conclusions: Adding apatinib to TP neoadjuvant chemotherapy significantly increased ORR, suggesting an advantage of anti-angiogenesis in ESCC. Clinical Trials.gov ID: ChiCTR-TRC-1800017662.

Targeting the Microenvironment in Esophageal Cancer

Esophageal cancer (EC) is the eighth most common type of cancer and the sixth leading cause of cancer-related deaths worldwide. At present, the clinical treatment for EC is based mainly on radical surgery, chemotherapy, and radiotherapy. However, due to the limited efficacy of conventional treatments and the serious adverse reactions, the outcome is still unsatisfactory (the 5-year survival rate for patients is less than 25%). Thus, it is extremely important and urgent to identify new therapeutic targets. The concept of tumor microenvironment (TME) has attracted increased attention since it was proposed. Recent studies have shown that TME is an important therapeutic target for EC. Microenvironment-targeting therapies such as immunotherapy and antiangiogenic therapy have played an indispensable role in prolonging survival and improving the prognosis of patients with EC. In addition, many new drugs and therapies that have been developed to target microenvironment may become treatment options in the future. We summarize the microenvironment of EC and the latest advances in microenvironment-targeting therapies in this review.

Apatinib induces endoplasmic reticulum stress-mediated apoptosis and autophagy and potentiates cell sensitivity to paclitaxel via the IRE-1α-AKT-mTOR pathway in esophageal squamous cell carcinoma

BACKGROUND

Apatinib, a novel vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase inhibitor, has been approved for the treatment of metastatic gastric cancer and other tumors. Apatinib exerts antiproliferative and proapoptotic effects in different kinds of cancer cells. However, the molecular mechanisms by which apatinib effective against esophageal squamous cell carcinoma (ESCC) have only been partially researched and whether it has a sensitizing effect on paclitaxel remains unclear.

MATERIALS AND METHODS

The effects of apatinib or paclitaxel on endoplasmic reticulum (ER) stress, autophagy, apoptosis and proliferation of ESCC cell lines were evaluated. Western blot and immunohistochemistry analyses were performed to detect the expression of related genes. The weight and volume of xenograft tumors in mice were measured.

RESULTS

In the current study, we elucidated the antiproliferative and ER-stress-mediated autophagy-inducing effects of apatinib on ECA-109 and KYSE-150 esophageal squamous cancer cells and identified the underlying mechanisms of its action. We demonstrated that apatinib not only inhibited the proliferation and induced the apoptosis of ESCC cells, but also activated ER stress and triggered protective autophagy. Moreover, inhibiting autophagy by chloroquine (CQ) enhanced the apatinib-induced apoptosis of ESCC cells through the IRE-1α-AKT-mTOR pathway. In addition, we showed, for the first time, the paclitaxel combined with apatinib and CQ exhibited the best antitumor effect on ESCC both in vivo and in vitro via the IRE-1α-AKT-mTOR pathway.

CONCLUSIONS

Our data showed that apatinib induced ER stress, autophagy and apoptosis in ESCC. Inhibiting autophagy by CQ enhanced apatinib-induced apoptosis. The combination of apatinib and CQ sensitized ESCC cells to paclitaxel to induce apoptosis through the IRE-1α-AKT-mTOR signaling pathway, thus providing the basis for its use in innovative anticancer therapeutic strategies.

Effectiveness and prognostic factors of apatinib treatment in patients with recurrent or advanced cervical carcinoma: A retrospective study

Background

Apatinib is an oral anti‐angiogenic drug, its efficacy and prognosis in cervical carcinoma are unclear. This study evaluates the effectiveness and prognostic factors of apatinib in the treatment of recurrent or advanced cervical carcinoma.

Methods

Patients with recurrent or advanced cervical cancer, who agreed to take apatinib, were recruited into this single‐center and retrospective study, and administrated apatinib with or without combination of chemo‐ or radio‐therapy until progressive disease (PD) or unacceptable toxicity.

Results

From March 2017 to February 2019, 53 patients were reviewed. Among them, 2 (3.77%) patients occurred complete response, 16 (30.19%) patients showed partial response, 27 (50.95%) patients had stable disease, and 8 (15.09%) patients had PD. The objective response rate and disease control rate (DCR) of these patients were 33.96% and 84.91%, respectively. The DCR of patients younger than 50, nonsquamous carcinoma, first‐line apatinib therapy, combined radiotherapy, lesions within radiation field, surgical history, and Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1 were significantly higher than other patients (p < 0.05). The median progression‐free survival (PFS) and overall survival (OS) were 6.0 months (95% CI: 4.43–7.57) and 8.0 months (95% CI: 6.52–9.48), respectively. The univariable and multivariable analysis showed that the patients with an ECOG performance status score of 2 and further line therapy were associated with poor prognosis in both PFS and OS (PFS: HR =8.35, p = 0.000; HR =6.66, p = 0.001; OS: HR = 7.40, p = 0.000; HR = 3.24, p = 0.039), respectively. The most common adverse effects (AEs) were hand‐foot syndrome (35.58%), hypertension (18.87%) and fatigue (15.09%). No grade 3 AEs and drug‐related death occurred.

Conclusion

The efficacy and prognosis of patients who are in good general condition and first‐line apatinib combination therapy may be better than other patients. But further phase III clinical trials should be taken to prove this hypothesis.

Cross-talk between next generation sequencing methodologies to identify genomic signatures of esophageal cancer

The asymptomatic behaviour of esophageal cancerous cells at early stages develops advanced clinical presentation of the disease, resulting in poor prognosis and curbed intervention of therapeutic modalities. The endeavours to detect diagnostic and prognostic markers have been proven futile at the clinical platform. While several biomarkers have been investigated, including CYFRA 21-1, carcinoembryonic antigen and squamous cell carcinoma antigen, their sensitivity has not proved consistently satisfactory across the various stages of esophageal cancer. Hence, there is an impending requirement of biomarkers for early diagnosis and better prognosis. In the recent past, next generation sequencing (NGS) tool has emerged as an important tool to highlight the hallmarks of esophageal cancer (EC). This review summarizes the changes/mutations occurred in tumor cells during carcinogenesis and addresses the contribution of NGS techniques, viz. whole genome sequencing (WGS), RNA-Sequencing and Exome sequencing (ES), in EC. Additionally, this review highlights the connection between the findings from these techniques. An effort has been made to emphasize the genes affected and involved signaling pathway in EC. Further, investigations of these mutated genes would not only shed light on the relevant genes to be studied but also help in the better management and cure through personalized therapy.

Combination effect of curcumin with docetaxel on the PI3K/AKT/mTOR pathway to induce autophagy and apoptosis in esophageal squamous cell carcinoma

BACKGROUND

Docetaxel (DTX) is widely used to treat many malignant tumors but has many adverse effects. Curcumin (CUR) also has effects on a variety of tumor cells and can reduce the toxicity and side effects of chemotherapy drugs and the occurrence of drug resistance. However, the combination of CUR and DTX for treating esophageal cancer has not been reported.

METHODS

Human esophageal squamous cell carcinoma (ESCC) KYSE150 and KYSE510 cells were treated with CUR or DTX alone or both drugs and cancer cell viability was detected by CCK8, apoptosis, scratch-healing and migration assays. Electron microscopy and Western blots were used. In vivo experiments were used observe anti-tumor effects.

RESULTS

CUR combined with DTX significantly inhibited the viability and migration of esophageal cancer cells (P<0.01) and further promoted the apoptosis of cancer cells. In addition, CUR induced autophagy in esophageal cancer cells when combined with DTX. DTX combined with CUR may induce apoptosis and autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway. The compound 3-methyladenine (3MA) inhibited the autophagy induced by DTX and CUR (DC), further accelerated apoptosis and inhibited the proliferation of esophageal cancer cells when combined with DC.

CONCLUSION

CUR combined with DTX induced apoptosis and autophagy of ESCC and probably worked through the PI3K/AKT/mTOR signaling pathway. The combination of the autophagy inhibitor, CUR and DTX may become a new treatment strategy for esophageal cancer.

Advances in targeted therapy for esophageal cancer

Esophageal cancer (EC) is one of the most lethal cancers in the world, and its morbidity and mortality rates rank among the top ten in China. Currently, surgical resection, radiotherapy and chemotherapy are the primary clinical treatments for esophageal cancer. However, outcomes are still unsatisfactory due to the limited efficacy and severe adverse effects of conventional treatments. As a new type of approach, targeted therapies have been confirmed to play an important role in the treatment of esophageal cancer; these include cetuximab and bevacizumab, which target epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF), respectively. In addition, other drugs targeting surface antigens and signaling pathways or acting on immune checkpoints have been continuously developed. For example, trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER-2), has been approved by the Food and Drug Administration (FDA) as a first-line treatment of HER-2-positive cancer. Moreover, the PD-L1 inhibitor pembrolizumab has been approved as a highly efficient drug for patients with PD-L1-positive or advanced esophageal squamous cell carcinoma (ESCC). These novel drugs can be used alone or in combination with other treatment strategies to further improve the treatment efficacy and prognosis of cancer patients. Nevertheless, adverse events, optimal dosages and effective combinations still need further investigation. In this review, we expound an outline of the latest advances in targeted therapies of esophageal cancer and the mechanisms of relevant drugs, discuss their efficacy and safety, and provide a clinical rationale for precision medicine in esophageal cancer.

Apatinib sensitizes chemoresistant NSCLC cells to doxetaxel via regulating autophagy and enhances the therapeutic efficacy in advanced and refractory/recurrent NSCLC

The prognosis of advanced non-small cell lung cancer (NSCLC) is poor; therefore, identifying novel treatment strategies for patients with NSCLC is important. The present study aimed to investigate the efficacy of apatinib plus docetaxel vs. docetaxel alone, as well as their effects on regulating autophagy markers in patients with advanced NSCLC. Furthermore, it was evaluated whether apatinib sensitized chemoresistant NSCLC cells to docetaxel via regulating autophagy. A total of 39 patients with advanced NSCLC were consecutively enrolled and treated with apatinib plus docetaxel (n=19) or docetaxel alone (n=20) for four treatment cycles. The treatment response, adverse events and expression levels of autophagy markers [(light chain 3 α (LC3A) and Beclin-1] were evaluated in tumor samples, which were obtained via biopsy, before treatment and after 2-cycle treatment. In addition, in a mechanistic in vitro experiment, apatinib, docetaxel, the autophagy activator rapamycin and the autophagy inhibitor 3-methyladenine (3-MA) were used to treat docetaxel-resistant A549 (A549/DTX) cells alone or in various combinations. The expression levels of LC3A, Beclin-1, poly (ADP) ribose polymerase (PARP) and phosphorylated (p)-AKT were detected via western blotting, while the cell apoptosis rate was detected with an Annexin V/PI assay. The overall remission rate (37 vs. 10%; P=0.047) and disease control rate (84 vs. 45%; P=0.011) were increased in the Apatinib plus docetaxel group compared with the Docetaxel group. Most of the adverse events were mild and tolerable, and there was no difference between the two groups except for total hypertension and hand-foot syndrome, which were higher in the Apatinib plus docetaxel group). Compared with the levels prior to treatment, Beclin-1 and LC3A remained unchanged post-treatment in the Apatinib plus docetaxel group, while they were increased in the Docetaxel group. Docetaxel increased LC3A, Beclin-1 and p-AKT expression levels, PARP cleavage and the cell apoptosis rate in A549/DTX cells, and rapamycin further enhanced, while 3-MA reduced these effects of docetaxel. Moreover, apatinib repressed LC3A, Beclin-1, p-AKT expression levels and promoted the cell apoptosis rate in A549/DTX cells and docetaxel-treated A549/DTX cells. In conclusion, apatinib synergize the effect of docetaxel in treating patients with advanced NSCLC and chemoresistant NSCLC cells via inhibiting autophagy.

Safety and Efficacy of Apatinib Monotherapy for Unresectable, Metastatic Esophageal Cancer: A Single-Arm, Open-Label, Phase II Study

LESSONS LEARNED

Patient compliance with the oral dosage treatment was good, with no need for hospitalization. Patients with tracheal and esophageal fistulas can take crushed apatinib by nutrient tube, with the same bioavailability and efficacy. Apatinib may be an effective and safe second- or further-line treatment for advanced esophageal cancer.

BACKGROUND

Apatinib is an inhibitor of vascular endothelial growth factor receptor-2 (VEGFR2), which is thought to play a role in esophageal cancer progression. Our goal was to evaluate the efficacy and safety of apatinib in patients with unresectable esophageal cancer and to examine whether VEGFR2 expression influenced the clinical response.

METHODS

This single-arm, open-label, investigator-initiated phase II study enrolled patients with advanced squamous cell carcinoma (SCC) or adenocarcinoma of the esophagus or esophagogastric junction who were admitted to Tianjin Medical University Cancer Institute and Hospital between August 2017 and January 2019. Apatinib monotherapy (500 mg/day) was given orally or via an enteral tube until disease progression, unacceptable toxicity, withdrawal, or death. Patients were followed until treatment was discontinued or death. The main endpoints were tumor response, progression-free survival (PFS), overall survival (OS), and adverse events (AEs).

RESULTS

Among 32 patients screened for inclusion, 30 were included in the safety and survival analyses (i.e., received apatinib), and 26 were included in the efficacy analysis (at least one imaging follow-up). Median follow-up time and exposure to apatinib were 5.34 months and 72 days, respectively. Among 26 patients included in the efficacy analysis, 2 had a partial response (PR; 7.7%) and 14 had stable disease (SD; 53.8%). The overall response rate (ORR) was 7.7%, and the disease control rate (DCR) was 61.5%. Median PFS and OS were 4.63 months (95% confidence interval, 2.11-7.16 months) and 6.57 months (4.90 months to not estimable), respectively. Fifteen patients (50.0%) experienced treatment-related AEs, most commonly hypertension (26.7%), diarrhea (20.0%), and hand-foot-skin reaction (10.0%). No patients had grade ≥4 treatment-related AEs.

CONCLUSION

Apatinib was effective as second- or further-line treatment for advanced esophageal cancer.

Apatinib suppresses tumor progression and enhances cisplatin sensitivity in esophageal cancer via the Akt/β-catenin pathway

Background

Esophageal cancer is the sixth leading cause of cancer-related mortality worldwide, which is partially due to limited progress of therapy. Apatinib, an inhibitor of VEGFR2, has a promising antitumor effect on malignancies. However, the underlying mechanism of its antitumor effect on esophageal cancer remains poorly understood.

Materials and methods

Eighteen pairs of frozen esophageal cancer and their para-cancer samples and 25 paraffin specimens from advanced esophageal cancer patients treated with cisplatin-based regimen were collected. The effects of apatinib on cell growth, cell apoptosis, cell cycle and invasion/migration of esophageal cancer cells were assessed. Bioinformatics, luciferase reporter, immunoprecipitation and immunofluorescence assays were conducted for mechanic investigation. Quantitative RT-PCR, western blotting and immunohistochemistry were used to measure the expression of functional genes. Xenograft tumor growth of mice was performed.

Results

We found that VEGFR2 was highly expressed in esophageal cancer and associated with poor efficacy of cisplatin-based treatment. Apatinib displayed profound actions against tumor cell growth of human esophageal cancer via promoting cell apoptosis and cell cycle arrest. Also, apatinib displayed the inhibitory effects on cell migration and invasion. Moreover, apatinib strongly suppressed the growth of esophageal cancer xenografts in mice. The effects of apatinib on esophageal cancer were partially dependent on its block of the VEGFR2/Akt/β-catenin pathway. Specifically, apatinib induced the degradation of β-catenin and decreased its transcriptional activity through Akt/GSK-3β repression. Further in vitro and in vivo studies revealed that low dose apatinib had a synergistic antitumor effect with cisplatin on esophageal cancer.

Conclusion

Our study indicates that apatinib suppresses tumor progression and enhances cisplatin sensitivity in esophageal cancer by deactivating the Akt/β-catenin pathway. These findings provide a theoretical foundation for using apatinib as an effective therapeutic drug for esophageal cancer.

The efficacy and safety of Apatinib mesylate in the treatment of metastatic osteosarcoma patients who progressed after standard therapy and the VEGFR2 gene polymorphism analysis

OBJECTIVE

The aim of this study was to investigate the efficacy and safety of Apatinib mesylate in the treatment of metastatic osteosarcoma patients who progressed after standard therapy and the VEGFR2 gene polymorphism analysis.

METHODS

Designed as a retrospective study, a total of 105 metastatic osteosarcoma patients who progressed after standard therapy were included in this study. The metastatic osteosarcoma patients received 500-750 mg Apatinib mesylate according to body surface area until disease progression or unacceptable toxicity with 28 days one cycle. Overall response was evaluated after two cycles Apatinib treatment, then progression-free survival (PFS) and overall survival (OS) were evaluated, and safety data were recorded. Additionally. peripheral blood and peripheral blood mononuclear cell (PBMC) specimens in the osteosarcoma patients were collected for the genotyping of VEGFR2 genetic variation and mRNA expression, respectively. Analysis on the association between genotype and baseline characteristics and VEGFR2 gene mRNA expression was analyzed. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate analysis was adjusted by Cox regression analysis.

RESULTS

The objective response rate (ORR) of the 105 metastatic osteosarcoma patients was 37.14%, disease control rate (DCR) was 77.14%, median PFS was 4.1 months, and median OS was 9.0 months. Regarding the VEGFR2 gene polymorphisms analysis, only - 906 T > C was of clinical significance. The prevalence of - 906 T > C in VEGFR2 among the study population was as follows: TT genotype 62 cases (59.05%), TC genotype 36 cases (34.29%) and CC genotype 7 cases (6.66%), minor allele frequency of - 906 T > C was 0.24. Compared with patients with TC/CC genotype, patients with TT genotype showed longer median PFS (5.0 versus 3.1 months, P = 0.011) and median OS (9.8 versus 7.6 months, P = 0.032). There was no correlation between the polymorphism and adverse reactions. Additionally, the mRNA expression in 69 randomly selected sample indicated that the mRNA expression of VEGFR2 of the patients with CC/TC genotypes were significantly higher than those of the TT genotype patients (P < 0.001).

CONCLUSION

Apatinib was safe and effective in the treatment of metastatic osteosarcoma patients who progressed after standard therapy. The clinical outcomes of Apatinib may be influenced by the polymorphism - 906 T > C of VEGFR2 through mediating the mRNA expression of VEGFR2.