Venous thromboembolic events and organ-specific occult cancers: a review and meta-analysis

Self-production of tissue factor-coagulation factor VII complex by ovarian cancer cells

BACKGROUND

Thromboembolic events are a major complication in ovarian cancer patients. Tissue factor (TF) is frequently overexpressed in ovarian cancer tissue and correlates with intravascular thrombosis. TF binds to coagulation factor VII (fVII), changing it to its active form, fVIIa. This leads to activation of the extrinsic coagulation cascade. fVII is produced by the liver and believed to be supplied from blood plasma at the site of coagulation. However, we recently showed that ovarian cancer cells express fVII transcripts under normoxia and that this transcription is inducible under hypoxia. These findings led us to hypothesise that ovarian cancer cells are intrinsically associated with TF-fVIIa coagulation activity, which could result in thrombosis.

METHODS

In this study, we examined whether ectopically expressed fVII could cause thrombosis by means of immunohistochemistry, RT-PCR, western blotting and flow cytometry.

RESULTS

Ectopic fVII expression occurs frequently in ovarian cancers, particularly in clear cell carcinoma. We further showed that ovarian cancer cells express TF-fVIIa on the cell surface under normoxia and that this procoagulant activity is enhanced by hypoxic stimuli. Moreover, we showed that ovarian cancer cells secrete microparticles (MPs) with TF-fVIIa activity. Production of this procoagulant secretion is enhanced under hypoxia.

CONCLUSION

These results raise the possibility that cancer cell-derived TF-fVIIa could cause thrombotic events in ovarian cancer patients.

Vitamin K, an example of triage theory: is micronutrient inadequacy linked to diseases of aging?

The triage theory posits that some functions of micronutrients (the approximately 40 essential vitamins, minerals, fatty acids, and amino acids) are restricted during shortage and that functions required for short-term survival take precedence over those that are less essential. Insidious changes accumulate as a consequence of restriction, which increases the risk of diseases of aging. For 16 known vitamin K-dependent (VKD) proteins, we evaluated the relative lethality of 11 known mouse knockout mutants to categorize essentiality. Results indicate that 5 VKD proteins that are required for coagulation had critical functions (knockouts were embryonic lethal), whereas the knockouts of 5 less critical VKD proteins [osteocalcin, matrix Gla protein (Mgp), growth arrest specific protein 6, transforming growth factor beta-inducible protein (Tgfbi or betaig-h3), and periostin] survived at least through weaning. The VKD gamma-carboxylation of the 5 essential VKD proteins in the liver and the 5 nonessential proteins in nonhepatic tissues sets up a dichotomy that takes advantage of the preferential distribution of dietary vitamin K1 to the liver to preserve coagulation function when vitamin K1 is limiting. Genetic loss of less critical VKD proteins, dietary vitamin K inadequacy, human polymorphisms or mutations, and vitamin K deficiency induced by chronic anticoagulant (warfarin/coumadin) therapy are all linked to age-associated conditions: bone fragility after estrogen loss (osteocalcin) and arterial calcification linked to cardiovascular disease (Mgp). There is increased spontaneous cancer in Tgfbi mouse knockouts, and knockdown of Tgfbi causes mitotic spindle abnormalities. A triage perspective reinforces recommendations of some experts that much of the population and warfarin/coumadin patients may not receive sufficient vitamin K for optimal function of VKD proteins that are important to maintain long-term health.

Venous thromboembolism in recurrent ovarian cancer-patients: A systematic evaluation of the North-Eastern German Society of Gynaecologic Oncology Ovarian Cancer Study Group (NOGGO)

INTRODUCTION

Systemic chemotherapy and surgery for patients with recurrent ovarian cancer (ROC) constitute a therapeutic challenge. Venous thromboembolism (VTE) seems to have a negative prognostic impact in patients with solid tumors including primary ovarian cancer in many series. Only limited contemporary data exist regarding the impact of VTE on ROC.

PATIENTS AND METHODS

Two large multicenter prospective controlled phase I/II-III studies on 2nd-line topotecan-based chemotherapy with platinum-sensitive or resistant ROC (N=525) were conducted on both operated and non-operative patients by the North-Eastern German Society of Gynaecologic Oncology Ovarian Cancer Study Group (NOGGO). Analysis was performed to identify incidence, predictors and prognosis of VTE. Survival analysis, univariate and Cox-regression analysis were performed to identify independent predictors of VTE, overall and progression free survival.

RESULTS

Thirty-seven (7%) VTE-episodes during chemotherapy were identified; 70% of them occurred within the first 2 months after initiation of chemotherapy. Ascites, as a sign of peritoneal carcinomatosis and advanced tumor disease, was identified as independent predictor of VTE. Advanced age and high BMI did not appear to affect significantly the VTE-incidence. High performance status, platinum-sensitivity, serous-papillary histology, lack of ascites and surgery appeared to positively affect survival by multivariate analysis. Overall survival and progression free survival were similar between the VTE and no-VTE patients.

CONCLUSION

ROC-patients appear to have the highest risk for developing VTE when ascites exists and during the first 2 months following chemotherapy initiation. In contrast to primary ovarian cancer, VTE could not be identified to affect overall survival in relapsed malignant ovarian disease.

Treatment with low-molecular-weight heparin for deep venous thrombosis complicated with digestive tract cancer: an analysis of 63 cases

AIM: To compare therapeutic efficacy of long-term low-molecular-weigh heparin treatment with routine Warfarin treatment for digestive tract cancer complicated with deep venous thrombosis.

METHODS: Sixty three digestive tract cancer patients complicated with deep venous thrombosis were retrospectively allotted from February 2005 to December 2006 either into long-term low-molecular-weight heparin treatment group (LMWH group) or into warfarin treatment group (routine care group). The bleeding rate, the rates of recurrent venous thromboembolism and the platelet counts of patients of both groups were analyzed.

RESULTS: In long-term LMWH group, bleeding occurred in 6 patients (18.8%) and the platelet count of 1 patient (3.1%) decreased below normal level, which did not show significant difference compared with routine care group (25.8% and 6.5%, respectively). However, at 12 months, recurrent venous thromboembolism occurred in 3 of 32 cases (9.4%), which showed significant difference compared with routine care group (29.0%, P < 0.05).

CONCLUSION: Long-term low-molecular-weight heparin, more convenient and more effective than routine warfarin therapy, is considered to be more effective for digestive tract cancer complicated with deep venous thrombosis.

Quality of life after iatrogenic bile duct injury: a case control study

OBJECTIVE

To compare quality of life (QOL) of patients following iatrogenic bile duct injuries (BDI) to matched controls.

SUMMARY BACKGROUND DATA

BDI complicate approximately 0.3% of all cholecystectomy procedures. The literature regarding impact on quality of life is conflicted as assessment using clinical determinants alone is insufficient.

METHODS

The medical outcomes study short form 36 (SF-36), a sensitive tool for quantification of life quality outcome, was used. The study group of iatrogenic BDI was compared with an age- and sex-matched group who underwent uncomplicated cholecystectomy. Telephone questionnaire using the SF-36 quality of life tool was administered to both groups at a median postoperative time of 12 years 8 months (range, 2 months -20 years).

RESULTS

Seventy-eight patients were referred with BDI but due to mortality (n = 10) and unavailability (n = 6) 62 participated. The age- and sex-matched control cohort had undergone uncomplicated cholecystectomy (n = 62). Comparison between groups revealed that 7 of 8 variables examined were statistically similar to those of the control group (physical functioning, role physical, bodily pain, general health perceptions, vitality and social functioning, and mental health index). Mean role emotional scores were slightly worse in the BDI group (46 vs. 50) but the significance was borderline (P = 0.045). Subgroup analysis by method of intervention for BDI did not demonstrate significant differences.

CONCLUSION

Quality of life of surviving patients following BDI compares favorably to that after uncomplicated laparoscopic cholecystectomy.

Coagulation, anticoagulation and pancreatic carcinoma

An increase in coagulation in patients with pancreatic carcinoma has long been documented. In this Review, we present what is known about the pathophysiology of increased coagulation in cancer and how it applies to pancreatic carcinoma. The relationship between the activation of coagulation or symptomatic thromboembolic disease and the development of pancreatic carcinoma is explored. Data on the relationship between thromboembolic disease and the behavior of pancreatic cancer before, during or after a diagnosis is made are also reviewed. Finally, the rationale and evidence for the use of oral anticoagulants or heparin in patients with pancreatic carcinoma is presented. This Review is a critical appraisal of what is known, and when the evidence is acceptable, on the subject of thromboembolism, anticoagulation, and treatment with anticoagulants in patients with pancreatic carcinoma.