Mass Spectrometry Proteomics Characterization of Plasma Biomarkers for Colorectal Cancer Associated With Inflammation

Background

Colorectal cancer (CRC) prognosis is determined by the disease stage with low survival rates for advanced stages. Current CRC screening programs are mainly using colonoscopy, limited by its invasiveness and high cost. Therefore, non-invasive, cost-effective, and accurate alternatives are urgently needed.

Objective and design

This retrospective multi-center plasma proteomics study was performed to identify potential blood-based biomarkers in 36 CRC patients and 26 healthy volunteers by high-resolution mass spectrometry proteomics followed by the validation in an independent CRC cohort (60 CRC patients and 44 healthy subjects) of identified selected biomarkers.

Results

Among the 322 identified plasma proteins, 37 were changed between CRC patients and healthy volunteers and were associated with the complement cascade, cholesterol metabolism, and SERPIN family members. Increased levels in CRC patients of the complement proteins C1QB, C4B, and C5 as well as pro-inflammatory proteins, lipopolysaccharide-binding protein (LBP) and serum amyloid A4, constitutive (SAA4) were revealed for first time. Importantly, increased level of C5 was verified in an independent validation CRC cohort. Increased C4B and C8A levels were correlated with cancer-associated inflammation and CRC progression, while cancer-associated inflammation was linked to the acute-phase reactant leucine-rich alpha-2-glycoprotein 1 (LRG1) and ceruloplasmin. Moreover, a 4-protein signature including C4B, C8A, apolipoprotein C2 (APO) C2, and immunoglobulin heavy constant gamma 2 was changed between early and late CRC stages.

Conclusion

Our results suggest that C5 could be a potential biomarker for CRC diagnosis. Further validation studies will aid the application of these new potential biomarkers to improve CRC diagnosis and patient care.

Contact system and intrinsic pathway activation in patients with advanced pancreatic cancer: a prospective cohort study

BACKGROUND

Despite high risk of venous thromboembolism (VTE) in patients with pancreatic cancer, there are little data on contact system activation in these patients.

OBJECTIVES

To quantify contact system and intrinsic pathway activation and subsequent VTE risk in patients with pancreatic cancer.

METHODS

Patients with advanced pancreatic cancer were compared with controls. Blood was drawn at baseline and patients were followed for 6 months. Complexes of proteases with their natural inhibitors, C1-esterase inhibitor (C1-INH), antithrombin (AT), or alpha-1 antitrypsin (α1at), were measured for complexes containing kallikrein (PKa:C1-INH), factor (F)XIIa (FXIIa:C1-INH), and FXIa (FXIa:C1-INH, FXIa:AT, FXIa:α1at). The association of cancer with complex levels was assessed in a linear regression model, adjusted for age, sex, and body mass index. In a competing risk regression model, we assessed associations between complex levels and VTE.

RESULTS

One hundred nine patients with pancreatic cancer and 22 controls were included. The mean age was 66 years (SD, 8.4) in the cancer cohort and 52 years (SD, 10.1) in controls. In the cancer cohort, 18 (16.7%) patients developed VTE during follow-up. In the multivariable regression model, pancreatic cancer was associated with increased complexes of PKa:C1-INH (P < .001), FXIa:C1-INH (P < .001), and FXIa:AT (P < .001). High FXIa:α1at (subdistribution hazard ratio, 1.48 per log increase; 95% CI, 1.02-2.16) and FXIa:AT (subdistribution hazard ratio, 2.78 highest vs lower quartiles; 95% CI, 1.10-7.00) were associated with VTE.

CONCLUSION

Complexes of proteases with their natural inhibitors were elevated in patients with cancer. These data suggest that the contact system and intrinsic pathway activation are increased in patients with pancreatic cancer.

ABO blood group type and risk of venous thromboembolism in patients with cancer

Venous thromboembolism (VTE) is common in patients with cancer. Although in the general population blood type non-O is associated with increased VTE risk, the impact of ABO blood type on risk of cancer-associated VTE has not been clarified. To determine the influence of ABO blood type on cancer-associated VTE risk, we conducted an analysis within the Vienna Cancer and Thrombosis Study, a prospective cohort study including patients with newly diagnosed or recurrent cancer observed for the primary outcome VTE. Restricted cubic spline analysis was performed and specific time-restricted subdistribution hazard ratios (SHR) were calculated to investigate the association between non-O blood type and VTE over time. One thousand, seven hundred and eight patients were included in the analysis (median follow-up time: 24 months; interquartile range: 10-24), and 151 patients developed VTE (8.8%). During the first 3 months of follow-up, there was no association between non-O blood type and VTE risk (SHR: 1.00; 95% confidence interval [CI]: 0.60-1.67). Thereafter, non-O blood type was associated with a higher VTE risk (SHR: 1.79; 95% CI: 1.12-2.85). Furthermore, non-O blood type was associated with increased VTE risk in patients with intermediate and low thrombotic risk tumor types (SHR: 1.73; 95% CI: 1.09-2.73) but not in very high-risk types (pancreatic, gastroesophageal, and brain cancer; SHR: 0.94; 95% CI: 0.55-1.61). This association was weakened after adjustment for factor VIII. Non-O blood type is a time-dependent predictor of VTE in patients with cancer. It is associated with increased VTE risk beyond 3 months of follow-up and in patients with intermediate- and low-risk tumor types.

Perioperative coagulation profile in major liver resection for cancer: a prospective observational study

Hepatectomy induced coagulation disturbances have been well studied over the past decade. Cumulative evidence supports the superiority of global coagulation analysis compared to conventional coagulation tests (i.e. PT or aPTT) for clinical decision making. Cancer, however, represents an acquired prothrombotic state and liver resection for cancer deserves a more thorough investigation. This prospective observational study was conducted to assess the perioperative coagulation status of patients undergoing major hepatectomies for primary or metastatic hepatic malignancy. Patients were followed up to the 10th postoperative day by serial measurements of conventional coagulation tests, plasma levels of coagulation factors and thrombin generation assay parameters. An abnormal coagulation profile was detected at presentation and included elevated FVIII levels, decreased levels of antithrombin and lag time prolongation in thrombin generation. Serial hematological data demonstrated increased vWF, FVIII, D-dimer, fibrinogen and decreased levels of natural anticoagulant proteins in the early postoperative period predisposing to a hypercoagulable state. The ratio of the anticoagulant protein C to the procoagulant FVIII was low at baseline and further declined postoperatively, indicating a prothrombotic state. Though no bleeding complications were reported, one patient experienced pulmonary embolism while under thromboprophylaxis. Overall, patients with hepatic carcinoma presenting for elective major hepatectomy may have baseline malignancy associated coagulation disturbances, aggravating the hypercoagulable state documented in the early postoperative period.

Cancer-associated venous thromboembolism

Cancer-associated thrombosis (including venous thromboembolism (VTE) and arterial events) is highly consequential for patients with cancer and is associated with worsened survival. Despite substantial improvements in cancer treatment, the risk of VTE has increased in recent years; VTE rates additionally depend on the type of cancer (with pancreas, stomach and primary brain tumours having the highest risk) as well as on individual patient's and cancer treatment factors. Multiple cancer-specific mechanisms of VTE have been identified and can be classified as mechanisms in which the tumour expresses proteins that alter host systems, such as levels of platelets and leukocytes, and in which the tumour expresses procoagulant proteins released into the circulation that directly activate the coagulation cascade or platelets, such as tissue factor and podoplanin, respectively. As signs and symptoms of VTE may be non-specific, diagnosis requires clinical assessment, evaluation of pre-test probability, and objective diagnostic testing with ultrasonography or CT. Risk assessment tools have been validated to identify patients at risk of VTE. Primary prevention of VTE (thromboprophylaxis) has long been recommended in the inpatient and post-surgical settings, and is now an option in the outpatient setting for individuals with high-risk cancer. Anticoagulant therapy is the cornerstone of therapy, with low molecular weight heparin or newer options such as direct oral anticoagulants. Personalized treatment incorporating risk of bleeding and patient preferences is essential, especially as a diagnosis of VTE is often considered by patients even more distressing than their cancer diagnosis, and can severely affect the quality of life. Future research should focus on current knowledge gaps including optimizing risk assessment tools, biomarker discovery, next-generation anticoagulant development and implementation science.

The versatile role of the contact system in cardiovascular disease, inflammation, sepsis and cancer

The human contact system consists of plasma proteins, which - after contact to foreign surfaces - are bound to them, thereby activating the zymogens of the system into enzymes. This activation mechanism gave the system its name - contact system. It is considered as a procoagulant and proinflammatory response mechanism, as activation finally leads to the generation of fibrin and bradykinin. To date, no physiological processes have been described that are mediated by contact activation. However, contact system factors play a pathophysiological role in numerous diseases, such as cardiovascular diseases, arthritis, colitis, sepsis, and cancer. Contact system factors are therefore an interesting target for new therapeutic options in different clinical conditions.

The Multifaceted Roles of Copper in Cancer: A Trace Metal Element with Dysregulated Metabolism, but Also a Target or a Bullet for Therapy

In the human body, copper (Cu) is a major and essential player in a large number of cellular mechanisms and signaling pathways. The involvement of Cu in oxidation-reduction reactions requires close regulation of copper metabolism in order to avoid toxic effects. In many types of cancer, variations in copper protein levels have been demonstrated. These variations result in increased concentrations of intratumoral Cu and alterations in the systemic distribution of copper. Such alterations in Cu homeostasis may promote tumor growth or invasiveness or may even confer resistance to treatments. Once characterized, the dysregulated Cu metabolism is pinpointing several promising biomarkers for clinical use with prognostic or predictive capabilities. The altered Cu metabolism in cancer cells and the different responses of tumor cells to Cu are strongly supporting the development of treatments to disrupt, deplete, or increase Cu levels in tumors. The metallic nature of Cu as a chemical element is key for the development of anticancer agents via the synthesis of nanoparticles or copper-based complexes with antineoplastic properties for therapy. Finally, some of these new therapeutic strategies such as chelators or ionophores have shown promising results in a preclinical setting, and others are already in the clinic.

Mechanisms and biomarkers of cancer-associated thrombosis

Cancer-associated thrombosis is a leading cause of non-cancer death in cancer patients and is comprised of both arterial and venous thromboembolism (VTE). There are multiple risk factors for developing VTE, including cancer type, stage, treatment, and other medical comorbidities, which suggests that the etiology of thrombosis is multifactorial. While cancer-associated thrombosis can be treated with anticoagulation, benefits of therapy must be balanced with the increased bleeding risks seen in patients with cancer. Although risk models exist for primary and recurrent VTE, additional predictors are needed to improve model performance and discrimination of high-risk patients. This review will outline the diverse mechanisms driving thrombosis in cancer patients, as well as provide an overview of biomarkers studied in thrombosis risk and important considerations when selecting candidate biomarkers.

Protease: Serpin complexes to assess contact system and intrinsic pathway activation

Mounting evidence suggests that a variety of disease states are pathophysiologically related to activation of the contact system in vivo. The plasma contact system is composed of a cascade of serine proteases initiated by surface activation of factor XII, which can then proceed through a procoagulant pathway by activating the intrinsic coagulation factor XI, or a proinflammatory pathway by activating prekallikrein. Serpins are the primary endogenous inhibitors of the contact system, which irreversibly inhibit their respective protease(s), forming a stable complex. We modified an existing assay strategy for detecting these complexes in plasma using ELISAs and determined the effect of preanalytical variation caused by anticoagulant selection and processing time. The assays were sensitive and specific to inherited deficiency of individual contact factors. We conclude that these assays are robust and represent a relatively simple approach to the assessment of contact factor activation in plasma samples.

Prothrombotic fibrin clot properties associated with increased endogenous thrombin potential and soluble P-selectin predict occult cancer after unprovoked venous thromboembolism

BACKGROUND

Compact fibrin clots relatively resistant to lysis are observed in patients at increased risk of venous thromboembolism (VTE) including malignancy. The citrullinated histone H3 (H3Cit) predicts VTE in cancer patients.

OBJECTIVES

We performed a cohort study to investigate whether abnormal clot properties predict cancer diagnosis following unprovoked VTE.

METHODS

In 369 consecutive patients aged <70 years without malignancy detected during routine screening, we determined plasma clot permeability (Ks ) and clot lysis time (CLT), along with several prothrombotic markers and H3Cit after 2 to 8 months since VTE.

RESULTS

During follow-up (median, 37; interquartile range, 33-39 months), malignancy was diagnosed in 22 patients (6%), who were older. This group had denser fibrin networks (-13% Ks ), impaired fibrinolysis (+25.5% CLT), increased endogenous thrombin potential (ETP,+7%), soluble P-selectin (+40.3%), and H3Cit (+169.2%) measured off anticoagulation after median 4 months since VTE. The Ks and CLT correlated with H3Cit (r = -.58 and r = .31, P < .05, respectively). The Kaplan-Meier survival analysis showed that reduced Ks (the first quartile, ≤6.2 × 10-9  cm2 ), prolonged CLT (the top quartile, >106 min), and higher ETP (the top quartile, >1657 nM × min) were predictors of cancer diagnosed during follow-up. The multivariable Cox proportional hazards model showed that patients with the prothrombotic clot phenotype (low Ks and long CLT) had the highest risk of cancer diagnosis [hazard ratio(HR), 23.4; 95% confidence interval (CI), 6.67-82.15].

CONCLUSIONS

Prothrombotic clot properties following unprovoked VTE might help identify patients at risk of a diagnosis of cancer within the first 3 years of follow-up.

Biomarkers of Cancer-Associated Thromboembolism

Venous thromboembolism is known to be associated with an increase in morbidity and mortality in patients with malignancy. Predictive laboratory biomarkers of venous thromboembolism (VTE) have long been sought after to improve outcomes and help guide clinical decision making. Previously studied biomarkers include C reactive protein (CRP), tissue factor expressing microparticles (TF MP), D-dimer, soluble P-selectin (sP-selectin), plasminogen activator inhibitor 1 (PAI-1), factor VIII, platelet count, and leukocyte counts. This chapter will focus on these possible biomarkers for cancer-associated thrombosis (CAT) with particular emphasis on the pathophysiology behind thrombosis formation as well as data from clinical studies in patients with malignancy. The incorporation of the above biomarkers into risk assessment tools to predict CAT will also be reviewed, as will risk factors for recurrent VTE in patients with malignancy. Further studies are ongoing to develop readily available biomarkers that can be incorporated into future risk assessment models with the goal of reducing morbidity and mortality due to cancer-associated thrombosis.

Pathophysiology 1. Mechanisms of Thrombosis in Cancer Patients

Thrombosis is a major cause of morbidity and mortality in cancer patients. The pathogenesis of blood coagulation activation in oncological patients is complex and involves both clinical and biological factors. Abnormalities in one or more coagulation test are common in cancer patients, even without thrombotic manifestations, indicating an ongoing hypercoagulable condition. Moreover, venous thromboembolism (VTE) can be the first symptom of an occult malignancy in an otherwise healthy individual. The levels of laboratory markers of activation of blood coagulation parallel the development of malignancy, being the coagulant mechanisms important for both thrombogenesis and tumor progression. Besides general clinical risk factors for VTE, also disease-specific clinical factors, i.e., type and stage of the tumor, and anticancer therapies increase the thrombotic risk in these patients. Furthermore, biological factors, including the cancer cell-specific prothrombotic properties together with the host cell inflammatory response to the tumor, are relevant as well as unique players in the pathogenesis of the cancer-associated hypercoagulability. Cancer cells produce and release procoagulant and fibrinolytic proteins, inflammatory cytokines, and procoagulant microparticles. They also express adhesion molecules binding to the receptors of host vascular cells (i.e., endothelial cells, platelets, and leukocytes), thereby stimulating the prothrombotic properties of these normal cells, including the shed of cell-specific microparticles and neutrophil extracellular traps. Of interest, several genes responsible for the cellular neoplastic transformation drive the programs of hemostatic properties expressed by cancer tissues. A better understanding of such mechanisms will help the development of novel strategies to prevent and treat the Trousseau's syndrome (i.e., cancer-associated thrombosis).

The coagulome and the oncomir: impact of cancer-associated haemostatic dysregulation on the risk of metastasis

Patients with cancer are at high risk of both thromboembolic and haemorrhagic events during the course of their disease. The pathogenesis of haemostatic dysfunction in cancer is complex and involves the interplay of multiple factors. There is growing evidence that interactions between malignancies and the coagulation system are not random but can represent coordinated and clinically-significant adaptations that enhance tumour cell survival, proliferation and metastatic potential. A detailed understanding of the interactions between the haemostatic systems and the pathophysiology of metastasis may not only provide insight into strategies that could potentially reduce the incidence of thrombohaemorrhagic events and complications, but could also help design strategies that are capable of modifying tumour biology, progression and metastatic potential in ways that could enhance anticancer therapies and thereby improve overall survival.

The polyphosphate-factor XII pathway drives coagulation in prostate cancer-associated thrombosis

Cancer is a leading cause of thrombosis. We identify a new procoagulant mechanism that contributes to thromboembolism in prostate cancer and allows for safe anticoagulation therapy development. Prostate cancer-mediated procoagulant activity was reduced in plasma in the absence of factor XII or its substrate of the intrinsic coagulation pathway factor XI. Prostate cancer cells and secreted prostasomes expose long chain polyphosphate on their surface that colocalized with active factor XII and initiated coagulation in a factor XII-dependent manner. Polyphosphate content correlated with the procoagulant activity of prostasomes. Inherited deficiency in factor XI or XII or high-molecular-weight kininogen, but not plasma kallikrein, protected mice from prostasome-induced lethal pulmonary embolism. Targeting polyphosphate or factor XII conferred resistance to prostate cancer-driven thrombosis in mice, without increasing bleeding. Inhibition of factor XII with recombinant 3F7 antibody reduced the increased prostasome-mediated procoagulant activity in patient plasma. The data illustrate a critical role for polyphosphate/factor XII-triggered coagulation in prostate cancer-associated thrombosis with implications for anticoagulation without therapy-associated bleeding in malignancies.

Is coagulation factor VIII a useful marker for colorectal carcinoma?

BACKGROUND AND OBJECTIVE

Increased thromboembolic events are well known in patients suffering from malignant diseases. In the following pilot study, we investigated the usefulness of coagulation factor VIII (FVIII) as a possible prognostic marker in patients with colorectal carcinoma (CRC).

METHODS

Plasma FVIII levels were measured in 79 patients with CRC, correlated with tumor characteristics, and compared with normal ranges of blood group (BG) 0 and BG A/AB/B and with 19 control patients.

RESULTS

In CRC patients mean FVIII levels were elevated compared with controls (BG 0: p=0.283, BG A/AB/B: p=0.001) and normal ranges. Interestingly, mean FVIII levels varied significantly in different blood groups (p=0.002). UICC stage I CRC patients presented with mean FVIII plasma levels within normal ranges, whereas UICC stage II-IV CRC patients presented with elevated FVIII plasma levels. In BG A/AB/B a significantly elevated FVIII level was found in G2 compared with G1 tumors (p< 0.001). Patients with elevated carcinoembryonic antigen also showed significantly elevated FVIII levels (p=0.050). FVIII levels at time of surgery did not correlate with survival within the first 2 years following surgery.

CONCLUSION

In this pilot study, we demonstrated that FVIII plasma levels are elevated in patients with CRC and affected by T-stage and differentiation of the tumor. Whether FVIII is a clinical useful marker needs to be tested in a larger cohort.

High factor VIII levels independently predict venous thromboembolism in cancer patients: the cancer and thrombosis study

OBJECTIVE

Patients with cancer are at an increased risk for venous thromboembolism (VTE). Clotting factor VIII activity (FVIII) has been established as risk factor of primary and recurrent VTE. We investigated FVIII as predictive parameter of VTE in cancer patients.

METHODS AND RESULTS

The prospective observational Cancer and Thrombosis Study (CATS) includes patients with newly diagnosed cancer or disease progression, study end point is symptomatic VTE. FVIII was measured on a Sysmex CA 7000 analyzer. Data on 840 patients (median age: 62 years, 25th to 75th percentile 53 to 68, 378 women) were available for analyses, of these 111 patients had hematologic malignancies and 729 solid cancer. During a median observation time of 495 days 62 events occurred. Cumulative probability of VTE after 6 months was 14% in patients with elevated FVIII-levels and 4% in those with normal levels (P=0.001). The association was strongest in younger patients: whereas in 40-year-old patients a 2-fold VTE risk per factor VIII increase of 20% was observed (HR=2.0 [95% CI: 1.5 to 2.7], P<0.0001), this association was still present but attenuated in older patients.

CONCLUSIONS

FVIII is independently associated with an increased risk of VTE in cancer patients. The association between FVIII and VTE risk declines with increasing age.

Proteomic profiling of urine for the detection of colon cancer

Background

Colorectal cancer is the second most common cause of cancer related death in the developed world. To date, no blood or stool biomarkers with both high sensitivity and specificity for potentially curable early stage disease have been validated for clinical use. SELDI and MALDI profiling are being used increasingly to search for biomarkers in both blood and urine. Both techniques provide information predominantly on the low molecular weight proteome (<15 kDa). There have been several reports that colorectal cancer is associated with changes in the serum proteome that are detectable by SELDI and we hypothesised that proteomic changes would also be detectable in urine.

Results

We collected urine from 67 patients with colorectal cancer and 72 non-cancer control subjects, diluted to a constant protein concentration and generated MALDI and SELDI spectra. The intensities of 19 peaks differed significantly between cancer and non-cancer patients by both t-tests and after adjusting for confounders using multiple linear regressions. Logistic regression classifiers based on peak intensities identified colorectal cancer with up to 78% sensitivity at 87% specificity. We identified and independently quantified 3 of the discriminatory peaks using synthetic stable isotope peptides (an 1885 Da fragment of fibrinogen and hepcidin-20) or ELISA (β2-microglobulin).

Conclusion

Changes in the urine proteome may aid in the early detection of colorectal cancer.