Clinical significance of vascular endothelial growth factor and endostatin levels in the differential diagnosis of malignant and benign ascites

Differential diagnosis of ascites: etiologies, ascitic fluid analysis, diagnostic algorithm

Ascites is the pathological accumulation of fluid within the peritoneal cavity. It often occurs as results of liver cirrhosis, malignant neoplasia, tuberculous infection, cardiac insufficiency, renal diseases, etc. Determining the etiology is an essential step in the management of patients with new-onset ascites. Abdominal paracentesis with appropriate ascitic fluid analysis is probably the most cost-effective method of determining the cause of ascites. We performed a literature search of PubMed and identified articles published in the field of ascites, to evaluate diagnostic values of various parameters in defining the etiologies of ascites and then provides diagnostic algorithm for patients with new-onset ascites. In patients with ascites, the constituent ratio of underlying etiology varies between developed and developing countries. It is a challenge to define the etiologies of ascites in developing countries. Routine ascitic fluid analysis should include the serum ascites albumin gradient (SAAG), total protein concentration, cell count and differential. Optional ascitic fluid analysis includes cholesterol, fluid culture, cytology, tumor markers, lactate dehydrogenase, adenosine deaminase (ADA), triglyceride, amylase, glucose, brain natriuretic peptide (BNP), etc. Our review evaluated diagnostic values of the above parameters in defining the etiologies of ascites. Diagnostic algorithm established in this review would provide a practical and convenient diagnostic strategy for clinicians in diagnosing patients with new-onset ascites.

Progress in the treatment of malignant ascites

Malignant ascites occurs as a symptom of the terminal stage of cancer, affecting the quality of life through abdominal distension, pain, nausea, anorexia, dyspnea and other symptoms. We describe the current main drug treatments in addition to surgery according to the traditional and new strategies. Traditional treatments were based on anti-tumor chemotherapy and traditional Chinese medicine treatments, as well as diuretics to relieve the patient's symptoms. New treatments mainly involve photothermal therapy, intestinal therapy and targeted immunity. This study emphasizes that both traditional and new therapies have certain advantages and disadvantages, and medication should be adjusted according to different periods of use and different patients. In conclusion, this article reviews the literature to systematically describe the primary treatment modalities for malignant ascites.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Acellular fraction from malignant effusions has cytotoxicity in breast cancer cells

Malignant ascites (MA) and malignant pleural effusion (MPE) are frequently developed in patients with metastatic cancer; however, the biological properties of these fluids have not been clarified. The present study explored the biological role of a low molecular fraction derived from malignant effusions on the activation of peripheral blood mononuclear cells and on the proliferation of breast cancer cells and fibroblast 55x cells. A <10-kDa fraction from effusions of 41 oncological patients and 34 individuals without cancer was purified, and its potential role in inhibiting nitric oxide (NO) production on lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells was explored, as well as its cytotoxicity on MCF-7 breast cancer cells and fibroblast 55x cells. A significant decrease in NO production was observed in the <10-kDa fraction from malignant effusions. In addition, the acellular fraction from MA decreased the viability of breast cancer cells without affecting human fibroblasts. These data support the presence of low molecular weight molecules in malignant samples with a specific role in inhibiting the defense mechanisms of peripheral blood mononuclear cells and decreasing the viability of breast cancer cells in vitro.

Development and validation a simple model for identify malignant ascites

The differential diagnosis of benign ascites and malignant ascites is incredibly challenging for clinicians. This research aimed to develop a user-friendly predictive model to discriminate malignant ascites from non-malignant ascites through easy-to-obtain clinical parameters. All patients with new-onset ascites fluid were recruited from January 2014 to December 2018. The medical records of 317 patients with ascites for various reasons in Renmin Hospital of Wuhan University were collected and reviewed retrospectively. Thirty-six parameters were included and selected using univariate logistic regression, multivariate logistic regression, and receiver operating characteristic (ROC) curve analyses to establish a mathematical model for differential diagnosis, and its diagnostic performance was validated in the other groups. Age, cholesterol, hypersensitivity C-reactive protein (hs-CRP) in serum, ascitic fluid adenosine deaminase (AF ADA), ascitic fluid lactate dehydrogenase (AF LDH) involvement in a 5-marker model. With a cut-off level of 0.83, the sensitivity, specificity, accuracy, and area under the ROC of the model for identifying malignant ascites in the development dataset were 84.7%, 88.8%, 87.6%, and 0.874 (95% confidence interval [CI], 0.822-0.926), respectively, and 80.9%, 82.6%, 81.5%, and 0.863 (95% CI,0.817-0.913) in the validation dataset, respectively. The diagnostic model has a similar high diagnostic performance in both the development and validation datasets. The mathematical diagnostic model based on the five markers is a user-friendly method to differentiate malignant ascites from benign ascites with high efficiency.

Phase I study of intraperitoneal bevacizumab for treating refractory malignant ascites

OBJECTIVE

This prospective, dose-escalation phase I study evaluated the safety and efficacy of intraperitoneal bevacizumab in managing refractory malignant ascites and explored the recommended dose of bevacizumab for further study.

METHODS

Patients with refractory malignant ascites were enrolled. Bevacizumab was intraperitoneal administered weekly at an initial dose of 2.5 mg/kg, with dose escalation to 5 and 7.5 mg/kg performed following the standard "3 + 3" rule. The total duration of treatment was 2 or 3 weeks.

RESULTS

Between December 2013 and September 2014, 13 patients (2.5 mg/kg, n = 4; 5 mg/kg, n = 3; 7.5 mg/kg, n = 6) with refractory malignant ascites were enrolled. Bevacizumab was well tolerated, and the most common treatment-related adverse events were abdominal pain (5/13), abdominal distension (2/13), and fatigue (2/13). The dose-limiting toxicity at 7.5 mg/kg was grade 3 bowel obstruction (1/13). The maximum tolerated dose (MTD) was not reached. The overall response and disease control rates were 7.7 and 61.5%, respectively.

CONCLUSIONS

Intraperitoneal bevacizumab safe and well tolerated for treating malignant ascites, and the MTD was not reached at doses of 2.5 to 7.5 mg/kg. Intraperitoneal bevacizumab at 7.5 mg/kg weekly is recommended for further study to verify its anti-tumor activity.Trial registration: Clinical Trials NCT01852409.

Clinical Value of Positron Emission Tomography-Computed Tomography Combined with Ultrasound in Detection of Primary Tumors in Patients with Malignant Ascites

OBJECTIVE

To investigate and discuss the clinical value of positron emission tomography-computed tomography (PET-CT) combined with ultrasound in detection of primary tumors in patients with malignant ascites (MA).

MATERIALS AND METHODS

A total of 122 malignant tumor patients with ascites as the initial symptom and 48 patients with benign ascites were enrolled in this study. All patients underwent PET-CT and abdominal B-ultrasound examinations. The corresponding specificity, sensitivity, accuracy rate, positive predictive value, and negative predictive value of PET-CT, abdominal B-ultrasound, and combined detection group were recorded, respectively, with pathological findings as the gold standards. Statistical Product and Service Solutions 17.0 software was used for statistical analysis. p < 0.05 suggested that the difference was statistically significant.

RESULTS

The detection rate of primary foci through PET-CT was 79.5%, of which the detection rate of primary foci of MA derived from gastric cancer was the highest. The detection rate of primary foci through B-ultrasound was 62.5%, which is the highest for MA derived from ovarian cancer. B-ultrasound had the highest specificity in diagnosing the primary foci of MA (73.2%), PET-CT had the highest sensitivity in diagnosing the primary foci of MA (91.7%), and PET-CT combined with abdominal B-ultrasound had the highest sensitivity and accuracy in diagnosing the primary foci of MA (98.1% and 89.1%, respectively). The diagnostic accuracy rate of B-ultrasound was the highest in detecting tumors >5 cm (77.0%), whereas that of PET-CT was the highest in detecting tumors of 3-5 cm (84.2%).

CONCLUSION

The PET-CT combined with ultrasound is conducive to improving the diagnostic efficiency for primary tumors in patients with MA.

Ascites modulates cancer cell behavior, contributing to tumor heterogeneity in ovarian cancer

Malignant ascites constitute a unique tumor microenvironment providing a physical structure for the accumulation of cellular and acellular components. Ascites is initiated and maintained by physical and biological factors resulting from underlying disease and forms an ecosystem that contributes to disease progression. It has been demonstrated that the cellular contents and the molecular signatures of ascites change continuously during the course of a disease. Over the past decade, increasing attention has been given to the characterization of components of ascites and their role in the progression of ovarian cancer, the most malignant gynecologic cancer in women. This review will discuss the role of ascites in disease progression, in terms of modulating cancer cell behavior and contributing to tumor heterogeneity.

Tumor markers in serum and ascites in the diagnosis of benign and malignant ascites

OBJECTIVE

To evaluate the values of 4 tumor markers in serum and ascites and their ascites/serum ratios in the identification and diagnosis of benign and malignant ascites.

MATERIALS AND METHODS

A total of 76 patients were selected as subjects and divided into malignant ascites group (45 cases) and benign ascites group (31 cases). Samples of ascites and serum of all hospitalized patients were collected before treatment. The levels of carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), cancer antigen 125 (CA125) and carbohydrate antigen 19-9 (CA19-9) were detected by chemiluminescence (CLIA) .

RESULTS

CEA, AFP and CA19-9 in both serum and ascites as well as CA125 in ascites were evidently higher in the malignant ascites group than in the benign ascites group (P<0.01). Malignant ascites was associated with elevated ascites/serum ratios for AFP and CA125 (P<0.01). The areas under receiver operating characteristic (AUROCs) of CEA and CA125 in ascites and the ratios of ascites/serum of AFP, CEA, CA125 and CA19-9 were all >0.7, suggesting certain values, while those of ascites CA19-9 and serum CEA were 0.697 and 0.629 respectively, indicating low accuracy in the identification and diagnosis of benign and malignant ascites. However, the AUROCs of the remaining indexes were <0.5, with no value for identification and diagnosis. Compared with single index, the sensitivity of combined detection increased significantly (P<0.05), in which the combined detection of CEA, CA19-9 and CA125 in ascites as well as the ratio of ascites/serum of CEA, CA19-9, CA125 and AFP had the highest sensitivity (98.4%) but with relevantly low specificity. Both sensitivity and specificity of combined detection should be comprehensively considered so as to choose the most appropriate index.

CONCLUSIONS

Compared with single index, combined detection of tumor markers in serum and ascites can significantly improve the diagnostic sensitivity and specificity.

Hemodynamic Consequences of Malignant Ascites in Epithelial Ovarian Cancer Surgery*: A Prospective Substudy of a Randomized Controlled Trial

Malignant ascites (MA) is most commonly observed in patients scheduled for epithelial ovarian cancer (EOC) surgery and is supposed as a major risk factor promoting perioperative hemodynamic deterioration. We aimed to assess the hemodynamic consequences of MA on systemic circulation in patients undergoing cytoreductive EOC surgery.This study is a predefined post-hoc analysis of a randomized controlled pilot trial comparing intravenous solutions within a goal-directed algorithm to optimize hemodynamic therapy in patients undergoing cytoreductive EOC surgery. Ascites was used to stratify the EOC patients prior to randomization in the main study. We analyzed 2 groups according to the amount of ascites (NLAS: none or low ascites [<500 mL] vs HAS: high ascites group [>500 mL]). Differences in hemodynamic variables with respect to time were analyzed using nonparametric analysis for longitudinal data and multivariate generalized estimating equation adjusting the analysis for the randomized study groups of the main study.A total of 31 patients in the NLAS and 16 patients in the HAS group were analyzed. Although cardiac output was not different between groups suggesting a similar circulatory blood flow, the HAS group revealed higher heart rates and lower stroke volumes during surgery. There were no differences in pressure-based hemodynamic variables. In the HAS group, fluid demands, reflected by the time to reindication of a fluid challenge after preload optimization, increased steadily, whereas stroke volume could not be maintained at baseline resulting in hemodynamic instability after 1.5 h of surgery. In contrast, in the NLAS group fluid demands were stable and stroke volume could be maintained during surgery. Clinically relevant associations of the type of fluid replacement with hemodynamic consequences were particularly observed in the HAS group, in which transfusion of fresh frozen plasma (FFP) was associated to an improved circulatory flow and reduced vasopressor and fluid demands, whereas the administration of artificial infusion solutions was related to opposite effects.Malignant ascites >500 mL implies increased fluid demands and substantial alterations in circulatory blood flow during cancer surgery. Fresh frozen plasma transfusion promotes recovering hemodynamic stability in patients with malignant ascites >500 mL, in whom artificial infusion solutions could not prevent from hemodynamic deterioration.

Endostatin's emerging roles in angiogenesis, lymphangiogenesis, disease, and clinical applications

BACKGROUND

Angiogenesis is the process of neovascularization from pre-existing vasculature and is involved in various physiological and pathological processes. Inhibitors of angiogenesis, administered either as individual drugs or in combination with other chemotherapy, have been shown to benefit patients with various cancers. Endostatin, a 20-kDa C-terminal fragment of type XVIII collagen, is one of the most potent inhibitors of angiogenesis.

SCOPE OF REVIEW

We discuss the biology behind endostatin in the context of its endogenous production, the various receptors to which it binds, and the mechanisms by which it acts. We focus on its inhibitory role in angiogenesis, lymphangiogenesis, and cancer metastasis. We also present emerging clinical applications for endostatin and its potential as a therapeutic agent in the form a short peptide.

MAJOR CONCLUSIONS

The delicate balance between pro- and anti-angiogenic factors can be modulated to result in physiological wound healing or pathological tumor metastasis. Research in the last decade has emphasized an emerging clinical potential for endostatin as a biomarker and as a therapeutic short peptide. Moreover, elevated or depressed endostatin levels in diseased states may help explain the pathophysiological mechanisms of the particular disease.

GENERAL SIGNIFICANCE

Endostatin was once sought after as the 'be all and end all' for cancer treatment; however, research throughout the last decade has made it apparent that endostatin's effects are complex and involve multiple mechanisms. A better understanding of newly discovered mechanisms and clinical applications still has the potential to lead to future advances in the use of endostatin in the clinic.

The clinical significance of vascular endothelial growth factor in malignant ascites

Ascites can be caused by many kinds of diseases. Patients with undetermined ascites represent a diagnostic challenge. The aims of this study were to determine the diagnostic value of vascular endothelial growth factor (VEGF) in differentiation of malignant ascites from benign ascites and to investigate the clinical value of ascitic VEGF as an independent prognostic parameter. The study included 462 consecutive patients with malignant ascites and 550 patients with benign ascites, VEGF level in ascites were determined by a sandwich enzyme-linked immunosorbent assay. The survival rate was calculated by the Kaplan-Meier method and the log-rank test. Multivariate survival analysis was performed using the Cox hazards model. In our study, we found VEGF levels in malignant ascites (676.59 ± 303.86 pg/ml) were significantly higher than those in benign ascites (218.37 ± 98.15 pg/ml) (P < 0.001). Meanwhile, we also found that VEGF levels in malignant ascites from patients with ovarian cancer were higher than those with other cancers. Areas under the receiver operating characteristic (ROC) curves of ascitic VEGF was 0.940. At a cutoff value of 319.5 pg/ml, VEGF yielded a sensitivity of 89.2 % and a specificity of 88.4 %. Patients associated with the high-level VEGF value (≥613.38 pg/ml) in malignant ascites exhibited poor mean survival rates (8.3 ± 0.52 vs 15.11 ± 0.66 months, P < 0.001). In a multivariate Cox regression model, higher ascitic VEGF was an independent prognostic factor for overall survival. Planned subgroup analysis was performed for patients with tumor node metastasis (TNM) stage I. In the univariate analysis, only ascitic VEGF was associated with overall survival. VEGF was found to have a highly accurate sensitivity and specificity, suggesting that it could be considered as a new biomarker to differentiate malignant ascites from the benign one. The high level of VEGF value in malignant ascites may be used as an independent prognostic factor in patients with all stages of cancer.

Impact of Ascites on the Perioperative Course of Patients With Advanced Ovarian Cancer Undergoing Extensive Cytoreduction: Results of a Study on 119 Patients

Objective

Cytoreductive surgery for epithelial ovarian cancer (EOC) is the cornerstone of multimodal therapy and considered as a high-risk surgery because of extensive multivisceral procedures. In most patients, ascites is present, but its impact on the surgical and clinical outcomes is unclear.

Methods

One hundred nineteen patients undergoing surgical cytoreduction because of EOC between 2005 and 2008 were included. All surgical data and the individual tumor pattern were collected systematically based on a validated documentation tool (intraoperative mapping of ovarian cancer) during primary surgery. The amount of ascites was determined at the time of surgery, and 3 groups were classified (no ascites [NOA, n = 56], low amount of ascites [< 500 mL, n = 42], and high amount of ascites [HAS > 500 mL, n = 21]).

Results

Group NOA compared with HAS showed less transfusions of packed red blood cells (median [quartiles], 0 [0–2] vs 0 [0–2] vs 3 [1–4] U; P < 0.001) and fresh frozen plasma (median [quartiles], 0 [0–2] vs 0 [0–4] vs 2 [2–6] U; P < 0.001). In addition, in patients with ascites, noradrenaline was administered more frequently and in higher doses. The postoperative length of stay in the intensive care unit was significantly shorter in the NOA versus the group with low amount of ascites and HAS (median [quartiles], 1 [0–1] vs 1 [0–2] vs 2 [1–5] days; P < 0.001). The hospital length of stay is extended in HAS compared with that in NOA (median [quartiles], 16 [13–20] vs 17 [14–22] vs 21 [17–41] days; P = 0.004). Postoperative complications were increased in patients with ascites at the time of surgery (P = 0.007).

Conclusions

The presence of a high amount of ascites at cytoreductive surgery because of EOC is associated with higher amounts of blood transfusions, whereas the length of hospital stay and the postoperative intensive care unit treatment are significantly prolonged compared with those of patients without ascites.

Anoikis resistance: an essential prerequisite for tumor metastasis

Metastasis is a multistep process including dissociation of cancer cells from primary sites, survival in the vascular system, and proliferation in distant target organs. As a barrier to metastasis, cells normally undergo an apoptotic process known as “anoikis,” a form of cell death due to loss of contact with the extracellular matrix or neighboring cells. Cancer cells acquire anoikis resistance to survive after detachment from the primary sites and travel through the circulatory and lymphatic systems to disseminate throughout the body. Because recent technological advances enable us to detect rare circulating tumor cells, which are anoikis resistant, currently, anoikis resistance becomes a hot topic in cancer research. Detailed molecular and functional analyses of anoikis resistant cells may provide insight into the biology of cancer metastasis and identify novel therapeutic targets for prevention of cancer dissemination. This paper comprehensively describes recent investigations of the molecular and cellular mechanisms underlying anoikis and anoikis resistance in relation to intrinsic and extrinsic death signaling, epithelial-mesenchymal transition, growth factor receptors, energy metabolism, reactive oxygen species, membrane microdomains, and lipid rafts.