Profile of bevacizumab in the treatment of platinum-resistant ovarian cancer: current perspectives

Orchestrated Action of AMPK Activation and Combined VEGF/PD-1 Blockade with Lipid Metabolic Tunning as Multi-Target Therapeutics against Ovarian Cancers

Ovarian cancer is one of the most lethal gynecological malignancies worldwide, and chemoresistance is a critical obstacle in the clinical management of the disease. Recent studies have suggested that exploiting cancer cell metabolism by applying AMP-activated protein kinase (AMPK)-activating agents and distinctive adjuvant targeted therapies can be a plausible alternative approach in cancer treatment. Therefore, the perspectives about the combination of AMPK activators together with VEGF/PD-1 blockade as a dual-targeted therapy against ovarian cancer were discussed herein. Additionally, ferroptosis, a non-apoptotic regulated cell death triggered by the availability of redox-active iron, have been proposed to be governed by multiple layers of metabolic signalings and can be synergized with immunotherapies. To this end, ferroptosis initiating therapies (FITs) and metabolic rewiring and immunotherapeutic approaches may have substantial clinical potential in combating ovarian cancer development and progression. It is hoped that the viewpoints deliberated in this review would accelerate the translation of remedial concepts into clinical trials and improve the effectiveness of ovarian cancer treatment.

Using GPCRs as Molecular Beacons to Target Ovarian Cancer with Nanomedicines

The five-year survival rate for women with ovarian cancer is very poor despite radical cytoreductive surgery and chemotherapy. Although most patients initially respond to platinum-based chemotherapy, the majority experience recurrence and ultimately develop chemoresistance, resulting in fatal outcomes. The current administration of cytotoxic compounds is hampered by dose-limiting severe adverse effects. There is an unmet clinical need for targeted drug delivery systems that transport chemotherapeutics selectively to tumor cells while minimizing off-target toxicity. G protein-coupled receptors (GPCRs) are the largest family of membrane receptors, and many are overexpressed in solid tumors, including ovarian cancer. This review summarizes the progress in engineered nanoparticle research for drug delivery for ovarian cancer and discusses the potential use of GPCRs as molecular entry points to deliver anti-cancer compounds into ovarian cancer cells. A newly emerging treatment paradigm could be the personalized design of nanomedicines on a case-by-case basis.

Structure-Activity Relationship of Cytotoxic Natural Products from Indonesian Marine Sponges

Indonesian marine natural products have been one of the most promising sources in the race to obtain potential drugs for cancer treatment. One of the primary producers of cytotoxic compounds is sponges. However, there are still limited sources of comprehensive reviews related to the relationship between the structure of isolated compounds and their cytotoxic activity. This review remarks the attempt to provide a preliminary guidance from the perspective of structure-activity relationship and its participation on marine natural products research. This guidance is segregated by the compound's classes and their cytotoxic targets to obtain and organized a reliable summary of inter-study of the isolated compounds and their cytotoxicity. Structure-activity relationship is well-known for its ability to tune the bioactivity of a specific compound, especially on synthetic organic chemistry and in silico study but rarely used on natural product chemistry. The present review is intended to narrow down the endless possibilities of cytotoxicity by giving a predictable structure-activity relationship for active compounds. In addition, bioactive framework leads were selected by uncovering a noticeable structure-activity relationship with the intervention of cytotoxic agents from natural sources, especially Indonesian marine sponge.

Graphical abstract

Examining heterogeneity of stromal cells in tumor microenvironment based on pan-cancer single-cell RNA sequencing data

Tumor tissues contain both tumor and non-tumor cells, which include infiltrated immune cells and stromal cells, collectively called the tumor microenvironment (TME). Single-cell RNA sequencing (scRNAseq) enables the examination of heterogeneity of tumor cells and TME. In this review, we examined scRNAseq datasets for multiple cancer types and evaluated the heterogeneity of major cell type composition in different cancer types. We further showed that endothelial cells and fibroblasts/myofibroblasts in different cancer types can be classified into common subtypes, and the subtype composition is clearly associated with cancer characteristic and therapy response.

The efficacy and safety profile of 2-weekly dosing of bevacizumab-containing chemotherapy for platinum-resistant recurrent ovarian cancer

Background

Despite being widely used, to date (June 2021), the regimen of bevacizumab 10 mg/kg every 2 weeks (Q2W) combined with chemotherapy is not approved in Japan for patients with platinum-resistant recurrent ovarian cancer. In this retrospective analysis, we evaluated the usage patterns of bevacizumab administered for platinum-resistant recurrent ovarian cancer.

Methods

We obtained clinical data from 155 Japanese medical facilities between November 2013 and December 2018 via a survey. Items included the number of cases of platinum-resistant recurrent ovarian cancer treated with bevacizumab according to dosage. For regimens including bevacizumab 10 mg/kg Q2W, additional information was requested relating to concomitantly administered agents, and the efficacy and safety of the regimen.

Results

Of 1739 bevacizumab-containing regimens reported in 1633 patients with recurrent ovarian cancer, 264 used 10 mg/kg Q2W. The overall response rate (ORR) with this regimen was 26.1%. Response rates varied according to regimen and were particularly favorable when bevacizumab 10 mg/kg Q2W was administered with paclitaxel (ORR, 53.0%) versus liposomal doxorubicin (15.0%; P < 0.0001) and irinotecan (7.7%; P < 0.028). The most frequent Grade ≥ 3 adverse events associated with bevacizumab 10 mg/kg Q2W were neutropenia (11.7%) and hypertension (11.7%). The most frequent bevacizumab-associated Grade ≥ 3 adverse events with bevacizumab plus paclitaxel versus bevacizumab plus liposomal doxorubicin were hypertension (9.0% versus 13.9%) and proteinuria (3.0% versus 8.4%).

Conclusions

Bevacizumab 10 mg/kg Q2W appears efficacious for patients with recurrent ovarian cancer, with a manageable toxicity profile. Approval of this regimen is clinically desirable for Japanese patients with ovarian cancer.

Pharmacological Inhibition of BAD Ser99 Phosphorylation Enhances the Efficacy of Cisplatin in Ovarian Cancer by Inhibition of Cancer Stem Cell-like Behavior

Platinum-based chemotherapy has been the standard treatment for ovarian cancer patients for approximately four decades. However, the prognosis of patients with advanced ovarian carcinoma remains dismal, mainly attributed to both dose-limiting toxicities of cisplatin and the high rate of chemo-resistant disease recurrence. Herein, both patient-derived and experimentally generated cisplatin-sensitive and -resistant ovarian cancer cell line models were used to delineate BADSer99 phosphorylation as an actionable target in ovarian cancer. BADSer99 phosphorylation was negatively associated with cisplatin sensitivity in ovarian cancer, and the inhibition of BADSer99 phosphorylation by point mutation induced apoptosis and reduced cisplatin IC₅₀. In addition, BAD phosphorylation was also shown to be associated with cancer stem cell-like properties. Henceforth, a novel small molecule which inhibits BAD phosphorylation specifically at Ser99 (NPB) was utilized. NPB promoted apoptosis and reduced 3D growth of bulk cancer cells and inhibited cancer stem cell-like properties in both cisplatin-sensitive and -resistant ovarian cancer cells. The combination of cisplatin with NPB exhibited synergistic effects in vitro. NPB in combination with cisplatin also achieved an improved outcome compared to either monotreatment in vivo, including suppression of the cancer stem cell population, an effect not observed with cisplatin treatment. Furthermore, NPB exhibited strong synergistic effects with the AKT inhibitor AZD5363, and significantly reduced its IC₅₀ in cells resistant to cisplatin treatment. These findings identify BADSer99 phosphorylation as an actionable and pharmacologically relevant target to improve outcomes of cisplatin treated ovarian cancer.

Porphyrinoid Drug Conjugates

Drawing inspiration from nature today remains a time-honored means of discovering the therapies of tomorrow. Porphyrins, the so-called "pigments of life" have played a key role in this effort due to their diverse and unique properties. They have seen use in a number of medically relevant applications, including the development of so-called drug conjugates wherein functionalization with other entities is used to improve efficacy while minimizing dose limiting side effects. In this Perspective, we highlight opportunities associated with newer, completely synthetic analogs of porphyrins, commonly referred to as porphyrinoids, as the basis for preparing drug conjugates. Many of the resulting systems show improved medicinal or site-localizing properties. As befits a Perspective of this type, our efforts to develop cancer-targeting, platinum-containing conjugates based on texaphyrins (a class of so-called "expanded porphyrins") will receive particular emphasis; however, the promise inherent in this readily generalizable approach will also be illustrated briefly using two other common porphyrin analogs, namely the corroles (a "contracted porphyrin") and porphycene (an "isomeric porphyrin").

BRD9 controls the oxytocin signaling pathway in gastric cancer via CANA2D4, CALML6, GNAO1, and KCNJ5

Background

First-line chemotherapeutic agents lead to remarkable activation treatment in cancers, but the side effects of these drugs also damage healthy cells. In some cases, drug resistance to chemotherapeutic agents is induced in cancer cells. The molecular mechanisms underlying such a side effect have been studied in a range of cancer types, yet little is known about how the adverse effects of chemotherapeutic drugs can be diminished by targeting bromodomain-containing protein 9 (BRD9) in gastric cancers.

Methods

We used two gastric cancer cell lines (MGC-803 and AGS) for comparison. We applied molecular and cellular techniques to measure cell survival and mRNA expression, investigated clinical data in the consensus of The Cancer Genome Atlas, and utilized high-throughput sequencing in MGC-803 cells and AGS cells for global gene expression analysis in inhibiting BRD9 conditions.

Results

Our studies showed that cancer cells with BRD9 overexpression, MGC-803 cells, were more sensitive to BRD9 inhibitors (i.e., BI9564 or BI7273) than AGS cells. The mechanism of BRD9 was related to the regulation of calcium voltage-gated channel auxiliary subunit alpha2 delta 4 (CANA2D4), calmodulin-like 6 (CALML6), guanine nucleotide binding protein (G protein), alpha activating activity polypeptide O (GNAO1) and Potassium Inwardly Rectifying Channel Subfamily J, Member 5 (KCNJ5) oncogenes in the oxytocin signaling pathway. BRD9 inhibitors could enhance the sensitivity of gastric cancer MGC-803 cells to adriamycin and cisplatin, so we may reduce the dosage of chemotherapeutic agents in curing gastric cancers with BRD9 over expression by combining BI9564 or BI7273 with adriamycin or cisplatin.

Conclusions

Our study elucidated the feasibility and effectiveness of inhibiting BRD9 to reduce the adverse effects of first-line chemotherapeutic agents in treating gastric cancer with BRD9 overexpression. This study provides a scientific theoretical basis for a chemotherapy regimen in gastric cancer with BRD9 overexpression.

Oxaliplatin Pt(IV) prodrugs conjugated to gadolinium-texaphyrin as potential antitumor agents

Described here is the development of gadolinium(III) texaphyrin-platinum(IV) conjugates capable of overcoming platinum resistance by 1) localizing to solid tumors, 2) promoting enhanced cancer cell uptake, and 3) reactivating p53 in platinum-resistant models. Side by side comparative studies of these Pt(IV) conjugates to clinically approved platinum(II) agents and previously reported platinum(II)-texaphyrin conjugates demonstrate that the present Pt(IV) conjugates are more stable against hydrolysis and nucleophilic attack. Moreover, they display high potent antiproliferative activity in vitro against human and mouse cell cancer lines. Relative to the current platinum clinical standard of care (SOC), a lead Gd(III) texaphyrin-Pt(IV) prodrug conjugate emerging from this development effort was found to be more efficacious in subcutaneous (s.c.) mouse models involving both cell-derived xenografts and platinum-resistant patient-derived xenografts. Comparative pathology studies in mice treated with equimolar doses of the lead Gd texaphyrin-Pt(IV) conjugate or the US Food and Drug Administration (FDA)-approved agent oxaliplatin revealed that the conjugate was better tolerated. Specifically, the lead could be dosed at more than three times (i.e., 70 mg/kg per dose) the tolerable dose of oxaliplatin (i.e., 4 to 6 mg/kg per dose depending on the animal model) with little to no observable adverse effects. A combination of tumor localization, redox cycling, and reversible protein binding is invoked to explain the relatively increased tolerability and enhanced anticancer activity seen in vivo. On the basis of the present studies, we conclude that metallotexaphyrin-Pt conjugates may have substantial clinical potential as antitumor agents.

Anticancer Activity of Gukulenin A Isolated from the Marine Sponge Phorbas gukhulensis In Vitro and In Vivo

Gukulenin A is a bis-tropolone tetraterpenoid isolated from the marine sponge Phorbas gukhulensis. In this study, we examined the anticancer activities of gukulenin A in ovarian cancer cell lines (A2780, SKOV3, OVCAR-3, and TOV-21G) and in an ovarian cancer mouse model generated by injecting A2780 cells. We found that gukulenin A suppressed tumor growth in A2780-bearing mice. Gukulenin A markedly inhibited cell viability in four ovarian cancer cell lines, including the A2780 cell line. Gukulenin A treatment increased the fraction of cells accumulated at the sub G1 phase in a dose-dependent manner and the population of annexin V-positive cells, suggesting that gukulenin A induces apoptotic cell death in ovarian cancer cells. In addition, gukulenin A triggered the activation of caspase-3, -8, and -9, and caspase inhibitors attenuated gukulenin A-induced A2780 cell death. The results suggest that gukulenin A may be a potential therapeutic agent for ovarian cancer.

First-line treatment of women with advanced ovarian cancer: focus on bevacizumab

Ovarian cancer is the fifth most common cause of cancer death in women in Europe. Despite the progress, almost 70% of the patients relapse. The standard treatment is cytoreductive surgery followed by platinumtaxane chemotherapy; in patients with a disseminated disease, one option is neoadjuvant chemotherapy with delayed surgery (ie, interval debulking surgery). The most important change in the last decades involved the schedule treatment and the addition of new drugs to first-line therapy. Because of the pathogenetic role of angiogenesis in solid-tumor growth and metastasis, research has been concentrated on anti-angiogenetic drug. Bevacizumab, the most promising anti-angiogenetic drug, is a humanized monoclonal IgG antibody that targets vascular endothelial growth factor receptor. It was approved on December 23, 2011 by the European Medicines Agency and on June 13, 2018 by the Food and Drug administration as first-line treatment in epithelial ovarian, fallopian tube, or primary peritoneal cancer stage III or IV in combination with carboplatin and paclitaxel. There are still some doubts, regarding the schedule, dosage, duration of the treatment, safety, and tolerability, both in first-line and in neoadjuvant chemotherapy treatments. This review tries to answer clinical practice questions and summarizes the evidence from Phase III studies, emerging data, and ongoing trials.

Recurrent colon perforation after discontinuation of bevacizumab for ovarian cancer

Bevacizumab (Bev) is an antiangiogenic drug used to treat various malignances, including ovarian cancer (OC). Bev is generally well-tolerated; however, it has a characteristic toxicity profile. In particular, gastrointestinal perforation (GIP) is a rare but serious side effect that can be lethal. A 55-year-old woman with recurrent OC had an episode of GIP during third-line chemotherapy comprising Bev and topotecan (TPT). Bev was discontinued while TPT was continued as monotherapy. Three months after discontinuation of Bev, the patient presented with left lower abdominal pain and was diagnosed with a second GIP. She had emergent surgery. One year later, she is still alive and healthy, and is continuing TPT. This is the first report of recurrent GIP after discontinuation of Bev. Our case suggests that physicians should be aware of GIP even after the discontinuation of Bev.

Targeted therapy and immunotherapy for platinum-refractory advanced ovarian adenosquamous carcinoma: a case report

Background

Ovarian adenosquamous carcinoma is an extremely rare type of ovarian histology. Platinum-refractory disease is also uncommon, but can be fatal because of the lack of available treatment options. To date, there is no study or case report on platinum-refractory ovarian adenosquamous carcinoma or its relevant treatment.

Case presentation

Herein, we report the case of a 38-year-old Chinese woman with platinum-refractory advanced ovarian adenosquamous carcinoma who received clinical benefit from poly adenosine diphosphate ([ADP] ribose) polymerase and programmed death-1 inhibitors after failure of prior multiline chemotherapies and antiangiogenic agents. The targeted therapy and immunotherapy-controlled disease deterioration and improved performance status. Thus far, the patient has survived longer than 15 months, and she is taking nivolumab as maintenance treatment.

Conclusion

Targeted therapy and immunotherapy may be options for rare categories of ovarian cancer, but this warrants more clinical evidence of efficacy and toxicity.

Bevacizumab combined with chemotherapy for ovarian cancer: an updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis was updated with results from a new trial and final data to reassess the efficacy and safety of bevacizumab combined with chemotherapy in ovarian cancer (OC).

METHODS

Randomized controlled trials (RCTs) were searched in PubMed, EMBASE, Cochrane clinical trials, Web of Science and clinicaltrial.gov databases. Outcomes included the progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and common adverse events. The hazard ratio (HR), risk ratio (RR) and odds ratio (OR) were pooled when the meta-analysis was performed.

RESULTS

Five RCTs with 4994 patients were included. In overall newly diagnosed OC, bevacizumab combined with chemotherapy did not significantly improve PFS (HR 0.85, 95%CI 0.70-1.02) or OS (HR 0.94, 95%CI 0.84-1.05). In the high-risk progression subgroup, the addition of bevacizumab significantly improved PFS (HR 0.76, 95%CI 0.68-0.84) and OS (HR 0.85, 95%CI 0.74-0.96). In recurrent OC, the addition of bevacizumab to chemotherapy significantly extended PFS (HR 0.53, 95%CI 0.45-0.63) and OS (HR 0.87, 95%CI 0.77-0.99). The ORR was improved (OR 2.37, 95%CI 1.99-2.82) in the overall population. Bevacizumab increased the incidence of hypertension (RR 21.27, 95%CI 9.42-48.02), proteinuria (RR 4.77, 95%CI 2.15-10.61), bleeding (RR 3.16, 95%CI 1.59-6.30), GI perforations (RR 2.76, 95%CI 1.51-5.03), arterial thrombosis events (RR 2.39, 95%CI 1.39-4.10) and venous thrombosis events (RR 1.43, 95%CI 1.04-1.96).

CONCLUSIONS

Bevacizumab combined with chemotherapy significantly improved PFS and OS in both patients with high-risk of progression and patients with recurrent OC, with an increased incidence of common adverse events. However, no statistically significant survival benefit was identified in the front-line settings.

Overexpression of Cathepsin L is associated with chemoresistance and invasion of epithelial ovarian cancer

Paclitaxel is recommended as a first-line chemotherapeutic agent against, ovarian cancer, however, the development of chemoresistance is a major obstacle in patients with aggressive ovarian cancer and results in recurrence after conventional therapy. The key molecule or mechanism associated with paclitaxel resistance in ovarian cancer still remains unclear. Cathepsin L (CTSL) is overexpressed in various cancers, however, the association between CTSL expression and paclitaxel resistance remains unclear. In the present study, we investigated the role of CTSL in paclitaxel-resistant SKOV3/TAX cells by CTSL silencing. Expression of CTSL was examined by immunohistochemistry and qRT-PCR in 58 clinical samples, and in SKOV3 cells and SKOV3/TAX cells. Effects of CTSL knockdown on ovarian cancer cell proliferation, apoptosis, migration, and invasion were also studied. The IHC and real-time PCR results showed that the difference of CTSL expression between ovarian cancer and the adjacent non-tumourous ovarian tissues was statistically significant. Western blot analysis showed that the CTSL was overexpressed in SKOV3/TAX cells and weakly detectable in paclitaxel-sensitive SKOV3 cells. Knocking-down of CTSL in ovarian cancer cells could decrease cell proliferation, migration, and invasion, and potentiate apoptosis induced by paclitaxel, suggesting CTSL may contribute to Paclitaxel resistance in ovarian cancer.

AP-1 confers resistance to anti-cancer therapy by activating XIAP

The underlying cause of treatment failure in many cancer patients is intrinsic and acquired resistance to chemotherapy. Recently, histone deacetylase (HDAC) inhibitors have developed into a promising cancer treatment. However, resistance mechanism induced by HDAC inhibitors remains largely unknown. Here we report that a HDAC inhibitor, JNJ-2648158 induced transcription of XIAP by activating AP-1 expression, which conferring resistance to chemotherapeutics. Our results showed that high expression of c-Fos caused by HDAC inhibitor promoted AP-1 formation during acquired resistance towards chemo-drugs, indicating an extremely poor clinical outcome in breast cancers and liver cancers. Our study reveals a novel regulatory mechanism towards chemo-drug resistance, and suggests that XIAP may serve as a potential therapeutic target in those chemo-resistant cancer cells.

Ovarian function following targeted anti-angiogenic therapy with bevacizumab

Improvements in cancer therapy have enabled further insight into the long-term effects of treatment, including the highly prevalent gonadal failure. The focus of treatment has been shifted to the preservation of fertility, which may be achieved by preventing ovarian toxicity. To this end, new molecular-targeted agents, including monoclonal antibodies, have been developed and used in a standard procedure for managing different cancers. However, the prolonged antitumor activity of these drugs may cause the emergence of new toxic effects. The aim of the present review was to discuss the leading toxic effect of the anti-angiogenic agent bevacizumab on ovarian function in female patients of reproductive age, which may be observed and expected during in clinical practice. The majority of bevacizumab-induced side effects are expected to be transient and eliminated within the anticipated drug clearance time frame; however, fundamental investigations on these effects are required for generating more evidence-based practice guidelines.

A brief review of the management of platinum-resistant-platinum-refractory ovarian cancer

Ovarian cancer, which ranks fifth in cancer deaths among women, is the most lethal gynecologic malignancy. Epithelial ovarian cancer (EOC) is the most common histologic type, with the 5-year survival for all stages estimated at 45.6%. This rate increases to more than 70% in the minority of patients who are diagnosed at an early stage, but declines to 35% in the vast majority of patients diagnosed at advanced stage. Recurrent EOC is incurable. Platinum sensitivity (or lack thereof) is a major determinant of prognosis. The current standard treatment is primary surgery followed by platinum-based chemotherapy. In recurrent platinum-resistant/platinum-refractory EOC, sequential single-agent salvage chemotherapy is superior to multiagent chemotherapy. Multiagent regimens increase toxicity without clear benefit; however, no preferred sequence of single agents is recommended. The impact of targeted therapies and immunotherapies on progression-free survival and overall survival, which remains dismal, is under active investigation. Currently, clinical trials offer the best hope for the development of a new treatment paradigm in this recalcitrant disease.

Thrombus leukocytes exhibit more endothelial cell-specific angiogenic markers than peripheral blood leukocytes do in acute coronary syndrome patients, suggesting a possibility of trans-differentiation: a comprehensive database mining study

Background

Current angiogenic therapies for cancers and cardiovascular diseases have not yet achieved expected benefits, which reflects the need for improved understanding of angiogenesis. In this study, we focused on solving the problem of whether tissues have different angiogenic potentials (APs) in physiological conditions and how angiogenesis is regulated in various disease conditions.

Methods

In healthy and diseased human and mouse tissues, we profiled the expression of 163 angiogenic genes, including transcription regulators (TRs), growth factors and receptors (GF/Rs), cytokines and chemokines (C/Cs), and proteases and inhibitors (P/Is). TRs were categorized as inflammatory, homeostatic, and endothelial cell-specific TRs, and C/Cs were categorized as pro-angiogenic, anti-angiogenic, and bi-functional C/Cs.

Results

We made the following findings: (1) the human heart, muscle, eye, pancreas, and lymph node are among the tissues with the highest APs; (2) tissues with high APs have more active angiogenic pathways and angiogenic C/C responses; (3) inflammatory TRs dominate regulation of all angiogenic C/Cs; homeostatic TRs regulate all to a lower extent, while endothelial cell-specific TRs mainly regulate pro-angiogenic and bi-functional C/Cs; (4) tissue AP is positively correlated with the expression of oxygen sensors PHD2 and HIF1B, VEGF pathway gene VEGFB, and stem cell gene SOX2; (5) cancers of the digestive system tend to have increased angiogenesis dominated by endothelial cell-specific pro-angiogenic pathways, while lung cancer and prostate cancer have significantly decreased angiogenesis; and (6) endothelial cell-specific pro-angiogenic pathways are significantly increased in thrombus-derived leukocytes in patients with acute coronary artery disease.

Conclusions

Our results demonstrate that thrombus-derived leukocytes express more endothelial cell-specific angiogenic markers to directly promote angiogenesis after myocardial infarction and that certain solid tumors may be more sensitive to anti-angiogenic therapies than others.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-017-0440-0) contains supplementary material, which is available to authorized users.

Antiangiogenic drugs used with chemotherapy for patients with recurrent ovarian cancer: a meta-analysis

Objective

The value of antiangiogenic inhibitors for patients with recurrent ovarian cancer has not been completely affirmed. Therefore, we aimed to assess the effectiveness and toxicities of various antiangiogenic drugs for the treatment of recurrent ovarian cancer.

Methods

In this meta-analysis, we searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases for complete randomized controlled trials. The searches were extended to May 15, 2016. The risk of bias of the included studies was evaluated via a Cochrane systematic evaluation, and the statistical analyses were performed using RevMan 5.2 software.

Results

In total, we included 8 randomized controlled trials involving 3,211 patients and divided them into 3 groups, vascular endothelial growth factor receptor inhibitors (VEGFRIs), vascular endothelial growth factor (VEGF) inhibitors (bevacizumab), and angiopoietin inhibitors (trebananib). The progression-free survival improved significantly in all the groups being given antiangiogenic drugs (hazard ratio [HR]: 0.55, 95% confidence interval [CI]: 0.45–0.67, I²=0%, P<0.00001 for the VEGFRI group; HR: 0.53, 95% CI: 0.45–0.63, I²=51%, P<0.00001 for the VEGF inhibitor group; HR: 0.67, 95% CI: 0.58–0.77, I²=0%, P<0.00001 for the trebananib group). Overall survival was obviously prolonged in the VEGFRI (HR: 0.76, 95% CI: 0.59–0.97, I²=0%, P=0.03), the VEGF inhibitor (HR: 0.87, 95% CI: 0.77–0.99, I²=0%, P=0.03), and trebananib groups (HR: 0.81, 95% CI: 0.67–0.99, I²=0%, P=0.04). The incidence of grade 3/4 side effects was different among the 3 groups, for example, proteinuria, hypertension, gastrointestinal perforation, and arterial thromboembolism were presented in the VEGF inhibitor group. Increased incidences of fatigue, diarrhea, and hypertension were seen in the VEGFRI group, and the trebananib group had a higher incidence of hypokalemia.

Conclusion

This meta-analysis showed that antiangiogenic drugs improved the progression-free survival. The VEGFRI, bevacizumab, and trebananib groups showed increased overall survival. Adding antiangiogenic drugs to chemotherapy treatment resulted in a higher incidence of grade 3/4 side effects, but these were manageable.

The role of surgery in advanced epithelial ovarian cancer

Nowadays, the standard management of advanced epithelial ovarian cancer is correct surgical staging and optimal tumour cytoreduction followed by platinum and taxane-based chemotherapy. Standard surgical staging consists of peritoneal washings, total hysterectomy, and bilateral salpingo-oophorectomy, inspection of all abdominal organs and the peritoneal surface, biopsies of suspicious areas or randomised biopsies if they are not present, omentectomy and para-aortic lymphadenectomy. After this complete surgical staging, the International Federation of Gynaecology and Obstetrics (FIGO) staging system for ovarian cancer is applied to determine the management and prognosis of the patient. Complete tumour cytoreduction has shown an improvement in survival. There are some criteria to predict cytoreduction outcomes based on serum biomarkers levels, preoperative imaging techniques, and laparoscopic-based scores. Optimised patient selection for primary cytoreduction would determine patients who could benefit from an optimal cytoreduction and might benefit from interval surgery. The administration of intraperitoneal chemotherapy after debulking surgery has shown an increase in progression-free survival and overall survival, especially in patients with no residual disease after surgery. It is considered that 3–17% of all epithelial ovarian carcinoma (EOC) occur in young women that have not fulfilled their reproductive desires. In these patients, fertility-sparing surgery is a worthy option in early ovarian cancer.