Tissue Factor Pathway Inhibitor 2: A Novel Biomarker for Predicting Asymptomatic Venous Thromboembolism in Patients with Epithelial Ovarian Cancer

Investigating the efficacy of tissue factor pathway inhibitor‑2 as a promising prognostic marker for ovarian cancer

Tissue factor pathway inhibitor-2 (TFPI2) is a tumor marker for diagnosing ovarian cancer and ovarian clear cell carcinoma (OCCC); however, its effectiveness as a prognostic marker remains unclear. The present study aimed to investigate the utility of TFPI2 as a prognostic marker for ovarian cancer. A total of 256 cases of ovarian cancer was collected at Nara Medical University (Kashihara, Japan) from January 2008 to January 2022. The majority of cases were serous carcinoma (109, 42.6%), followed by OCCC (66, 25.8%), mucinous carcinoma (40, 15.6%), endometrial carcinoma (15, 5.9%), and other (26, 10.2%). The median preoperative serum TFPI2 for ovarian cancer was 219.0 (82.5-5,824.2) pg/ml. Overall survival (OS) of patients with non-OCCC and OCCC was calculated using the cut-off value determined obtained through receiver operating characteristic curve analysis. Cut-off values of TFPI2 for OS were 201 for non-OCCC and 255 pg/ml for OCCC. In univariate analysis, OS was significantly elevated in patients with non-OCCC and OCCC who had TFPI2 levels ≥201 pg/ml (P<0.001) and ≥255 pg/ml (P=0.036), respectively. Progression-free survival (PFS) was significantly elevated in patients with non-OCCC and OCCC who had TFPI2 levels ≥201 and ≥255 pg/ml (both P<0.001), respectively. Multivariate analysis revealed that OS was significantly higher in patients with non-OCCC who had TFPI2 levels ≥201 pg/ml (P=0.021), while PFS was significantly higher in patients with OCCC who had TFPI2 levels ≥255 pg/ml (P=0.020). These findings suggest that TFPI2 is a potential prognostic marker for ovarian carcinoma.

Long Non-Coding RNAs: Bridging Cancer-Associated Thrombosis and Clinical Outcome of Ovarian Cancer Patients

Ovarian cancer (OC) and venous thromboembolism (VTE) have a close relationship, in which tumour cells surpass the haemostatic system to drive cancer progression. Long non-coding RNAs (lncRNAs) have been implicated in VTE pathogenesis, yet their roles in cancer-associated thrombosis (CAT) and their prognostic value are unexplored. Understanding how these lncRNAs influence venous thrombogenesis and ovarian tumorigenesis may lead to the identification of valuable biomarkers for VTE and OC management. Thus, this study evaluated the impact of five lncRNAs, namely MALAT1, TUG1, NEAT1, XIST and MEG8, on a cohort of 40 OC patients. Patients who developed VTE after OC diagnosis had worse overall survival compared to their counterparts (log-rank test, p = 0.028). Elevated pre-chemotherapy MEG8 levels in peripheral blood cells (PBCs) predicted VTE after OC diagnosis (Mann-Whitney U test, p = 0.037; Χ2 test, p = 0.033). In opposition, its low levels were linked to a higher risk of OC progression (adjusted hazard ratio (aHR) = 3.00; p = 0.039). Furthermore, low pre-chemotherapy NEAT1 levels in PBCs were associated with a higher risk of death (aHR = 6.25; p = 0.008). As for the remaining lncRNAs, no significant association with VTE incidence, OC progression or related mortality was observed. Future investigation with external validation in larger cohorts is needed to dissect the implications of the evaluated lncRNAs in OC patients.

Tissue factor pathway inhibitor 2: Current understanding, challenges, and future perspectives

AIM

Tissue factor pathway inhibitor 2 (TFPI2) is a structural homolog of tissue factor pathway inhibitor 1 (TFPI1). Since TFPI2 is a placenta-derived protein, dynamic changes in TFPI2 levels may be related to pregnancy-related diseases. Furthermore, TFPI2 has been reported to be a novel serum biomarker for detecting ovarian cancer, especially clear cell carcinoma (CCC). This review aims to summarize the current knowledge on the biological function of TFPI2, highlight the major challenges that remain to be addressed, and discuss future research directions.

METHODS

Papers published up to March 31, 2023 in the PubMed and Google Scholar databases were included in this review. We also provide novel complementary information to what is known about the action of TFPI2.

RESULTS

Since TFPI2 concentrations in the blood of pregnant women, preeclampsia patients, and cancer patients vary greatly, its pathophysiological functions have attracted attention. Downregulation of TFPI2, a tumor-suppressor gene, by hypermethylation may contribute to the progression of several cancers. On the other hand, TFPI2 overexpressed in CCC is a risk factor for the development of thrombosis, possibly through inhibition of plasmin activity. However, agreement on the biological function of TFPI2 is still lacking and there are many scientific questions to be addressed. In particular, the lack of international standardization for the quantification of TFPI2 concentrations makes it difficult for researchers and clinicians to evaluate, pool, and compare data from different studies across countries.

DISCUSSION

This review summarizes current understandings and challenges in TFPI2 research and discusses future perspectives.

The role of tissue factor pathway inhibitor 2 in the coagulation and fibrinolysis system

AIM

Tissue factor (TF), the primary initiator of the extrinsic coagulation pathway, contributes to the generation of a hypercoagulable and prothrombotic state in cancer patients. TF pathway inhibitor (TFPI) is a major inhibitor of TF-mediated coagulation pathway. The two proteins, TFPI1 and TFPI2, are encoded by separate genes. Indeed, various cancer patients with venous thromboembolism (VTE) had significantly lower TFPI1 levels than those without VTE. In contrast, serum TFPI2 level was found to increase in ovarian cancer patients with VTE. It remains unclear why TFPI2, unlike TFPI1, is elevated in ovarian cancer patients with VTE. The aim of this review is to explore the pathophysiological role of TFPI2 on the coagulation and fibrinolysis system.

METHODS

A literature search was performed from inception to April 30, 2022 in the PubMed and Google Scholar databases.

RESULTS

TFPI1 and TFPI2 are homologs with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 inhibits TF/factor VIIa (FVIIa) catalyzed factor X (FX) activation. On the other hand, TFPI2 is unlikely to affect TF-initiated thrombin generation, but it has strong inhibitory activity against plasmin. Plasmin is involved in fibrin degradation, clot lysis, and inactivation of several coagulation factors (such as FV, FVIII, FIX, and FX). TFPI2 may increase the risk of VTE by inhibiting plasmin-dependent fibrinolysis.

CONCLUSION

TFPI1 and TFPI2 may have different key functions in regulating the coagulation and fibrinolytic systems.

Tissue Factor Pathway Inhibitors as Potential Targets for Understanding the Pathophysiology of Preeclampsia

BACKGROUND

Preeclampsia is a hypertensive disorder of pregnancy that causes maternal and perinatal morbidity and mortality worldwide. Preeclampsia is associated with complex abnormalities of the coagulation and fibrinolytic system. Tissue factor (TF) is involved in the hemostatic system during pregnancy, while the Tissue Factor Pathway Inhibitor (TFPI) is a major physiological inhibitor of the TF-initiated coagulation cascade. The imbalance in hemostatic mechanisms may lead to a hypercoagulable state, but prior research has not comprehensively investigated the roles of TFPI1 and TFPI2 in preeclamptic patients. In this review, we summarize our current understanding of the biological functions of TFPI1 and TFPI2 and discuss future directions in preeclampsia research.

METHODS

A literature search was performed from inception to 30 June 2022 in the PubMed and Google Scholar databases.

RESULTS

TFPI1 and TFPI2 are homologues with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 is an essential physiological inhibitor of the TF-initiated extrinsic pathway of coagulation. On the other hand, TFPI2 inhibits plasmin-mediated fibrinolysis and exerts antifibrinolytic activity. It also inhibits plasmin-mediated inactivation of clotting factors and maintains a hypercoagulable state. Furthermore, in contrast to TFPI1, TFPI2 suppresses trophoblast cell proliferation and invasion and promotes cell apoptosis. TFPI1 and TFPI2 may play important roles in regulating the coagulation and fibrinolytic system and trophoblast invasion to establish and maintain successful pregnancies. Concentrations of TF, TFPI1, and TFPI2 in maternal blood and placental tissue are significantly altered in preeclamptic women compared to normal pregnancies.

CONCLUSIONS

TFPI protein family may affect both the anticoagulant (i.e., TFPI1) and antifibrinolytic/procoagulant (i.e., TFPI2) systems. TFPI1 and TFPI2 may function as new predictive biomarkers for preeclampsia and navigate precision therapy.

The Endometriotic Neoplasm Algorithm for Risk Assessment (e-NARA) Index Sheds Light on the Discrimination of Endometriosis-Associated Ovarian Cancer from Ovarian Endometrioma

BACKGROUND

Magnetic resonance (MR) relaxometry provides a noninvasive tool to discriminate endometriosis-associated ovarian cancer (EAOC) from ovarian endometrioma (OE) with high accuracy. However, this method has a limitation in discriminating malignancy in clinical use because the R2 value depends on the device manufacturer and repeated imaging is unrealistic. The current study aimed to reassess the diagnostic accuracy of MR relaxometry and investigate a more powerful tool to distinguish EAOC from OE.

METHODS

This retrospective study was conducted at our institution from December, 2012, to May, 2022. A total of 150 patients were included in this study. Patients with benign ovarian tumors (n = 108) mainly received laparoscopic surgery, and cases with suspected malignancy (n = 42) underwent laparotomy. Information from a chart review of the patients' medical records was collected.

RESULTS

A multiple regression analysis revealed that the age, the tumor diameter, and the R2 value were independent malignant predicting factors. The endometriotic neoplasm algorithm for risk assessment (e-NARA) index provided high accuracy (sensitivity, 85.7%; specificity, 87.0%) to discriminate EAOC from OE.

CONCLUSIONS

The e-NARA index is a reliable tool to assess the probability of malignant transformation of endometrioma.