The role of thromboprophylaxis in cancer patients: emerging data

Risk of Venous Thromboembolism for Patients with Pancreatic Ductal Adenocarcinoma Undergoing Preoperative Chemotherapy Followed by Surgical Resection

BACKGROUND

Pancreatic ductal adenocarcinoma (PDA) is associated with a hypercoagulable state, resulting in a high risk of venous thromboembolism (VTE). Risk of VTE is well established for patients receiving chemotherapy for advanced disease and during the perioperative period for patients undergoing surgical resection. However, data are lacking for patients undergoing neoadjuvant treatment followed by resection, who may have a unique risk of VTE because of exposure to both chemotherapy and surgery.

METHODS

The study included patients with PDA who underwent neoadjuvant therapy followed by surgery from 2007 to June 2017. Development of VTE was evaluated from the start of treatment through the 90-day postoperative period. Risk factors including demographic, treatment, and laboratory variables were evaluated.

RESULTS

The study investigated 426 patients receiving neoadjuvant therapy before surgical resection. Of these patients, 20% had a VTE within 90 days postoperatively (n = 87), and 70% of the VTE occurred during the postoperative period. The VTE included pulmonary embolism (30%), deep vein thrombosis (33%), and thrombosis of the portal vein (PV)/superior mesenteric vein (SMV) (40%). A pretreatment hemoglobin level lower than 10 g/dL and a platelet count higher than 443 were independently associated with VTE during neoadjuvant treatment. The independent predictors of postoperative VTE were a body mass index higher than 35 kg/m2, a preoperative platelet-to-lymphocyte ratio higher than 260, resection with distal pancreatectomy with celiac axis resection/total pancreatectomy, PV/SMV resection, and longer operative times. Development of VTE was associated with worse overall and disease-free survival and an independent predictor of survival and decreased likelihood of receiving adjuvant chemotherapy.

CONCLUSIONS

Venous thromboembolism during neoadjuvant therapy and the subsequent perioperative period is common and has a significant impact on outcome. Further study into novel thromboprophylaxis measures or protocols during neoadjuvant treatment and the perioperative period is warranted.

Meeting Report EuroG20 Meeting on Cancer-Associated Thrombosis (CAT) Bergamo, Italy 7 April 2016

The EuroG20 meeting on cancer-associated thrombosis (CAT) convened in Bergamo, Italy on 7 April 2016 to discuss a selection of controversial topics in CAT management. This satellite meeting besides ICTHIC in Bergamo has the objective to propose an European Guidance on CAT in various complex situations where evidence-based guidelines are lacking, driven by eminence-based thoughts of 20 experts and key opinion leaders in thrombosis from EU area and 8 experts from the rest of the world.

Pancreatic cancer and thromboembolic disease, 150 years after Trousseau

The connection between pancreatic cancer and venous thrombosis has been discussed for almost 150 years. The exact pathophysiological mechanisms are still partly understood, but it is known that pancreatic cancer induces a prothrombotic and hypercoagulable state and genetic events involved in neoplastic transformation (e.g., KRAS, c-MET, p53), procoagulant factors [e.g., tissue factor (TF), platelet factor 4 (PF4), plasminogen activator inhibitor type 1 (PAI-1)], mucin production (e.g., through activation of P- and L-selectin) and pro-inflammatory factors [e.g., cytokines, cyclooxygenase-2 (COX-2)] may be implicated. Also pancreatitis, both acute and chronic, is associated with increased risk of venous thrombosis, but in this circumstance a direct inflammatory process may be more important. This article discusses the incidence, treatment and outcome of venous thromboembolism (VTE) complicating pancreatic disease, with special emphasis on new knowledge obtained during the last fifteen years.

Thromboprophylaxis in ambulatory lung cancer treatment

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, are common problems experienced by patients with lung cancer that can impact treatment plans, prognoses, and survival. Patients with lung cancer are at greatest risk for development of VTE in the ambulatory care treatment setting. Literature does exist on VTE management for medical and surgical oncology inpatients, as well as clinical guidelines for inpatient prophylaxis; however, published evidence is lacking on outpatient risk and thromboprophylaxis in medical oncology outpatients, particularly patients with lung cancer. Because patients with lung cancer treated in the ambulatory setting have established risks for VTE, they may benefit from thromboprophylaxis. Clinical guidelines for outpatient thromboprophylaxis direct the clinical practice for thromboprophylaxis in lung cancer treatment. The purpose of the current article is to explore the VTE risks associated with ambulatory lung cancer treatment and to review the recommended guidelines for thromboprophylaxis to guide clinical decision making for patients with lung cancer.

Inhibition of tissue factor pathway inhibitor increases the sensitivity of thrombin generation assay to procoagulant microvesicles

Patients with cancer have a seven-fold to 10-fold increased risk of developing venous thromboembolism (VTE). Circulating microvesicles could be a predictive biomarker for VTE in cancer. Thrombin generation assay (TGA) is a useful technique to detect procoagulant activity of microvesicles. However, TGA suffers from a lack of sensitivity due to the presence of tissue factor pathway inhibitor (TFPI) in plasma. The aim of the study was to improve the sensitivity of TGA to tissue factor by limiting the interference of TFPI. Serial dilutions of MDA-MB231 cells were incubated for 45 min at 37°C to generate microvesicles. Samples were then centrifuged and supernatants that contain microvesicles were used for TGA. Normal pooled plasma was incubated with inhibitor of TFPI or was diluted twice to decrease plasma level of TFPI. Lagtime was used as a surrogate marker of TGA to detect procoagulant activity of microvesicles. Inhibition of TFPI decreased twice the cell concentration needed for a significant reduction of lagtime and decreased 2.4-fold the intraassay variability. Plasma dilution had no impact on the TGA sensitivity when TGA was triggered by microvesicles derived from MDA-MB-231. Thrombin generation is a very sensitive method to study the procoagulant activity of tissue factor bearing microvesicles. The sensitivity can be increased by inhibition of TFPI with specific monoclonal antibody against its Kunitz domain I. A two times plasma dilution is an interesting cheaper alternative to study the procoagulant activity of microvesicles by TGA with a good sensitivity, especially when low plasma quantities are available.

Portal venous system thrombosis after pancreatic resection

BACKGROUND

Portal venous system thrombosis (PVST) is a rare, potentially fatal complication after pancreatic resection. The aim of this study was to assess the incidence, presenting symptoms, management, and treatment of PVST in a large cohort of patients.

METHODS

Prospectively collected data on patients undergoing pancreatic resection between 1997 and 2009 were reviewed retrospectively. Preoperative and postoperative imaging were analyzed for the presence or absence of venous thrombi. All patients received standard thromboprophylaxis with low-molecular-weight heparin (LMWH).

RESULTS

Of 516 pancreatic resections performed, 18 (3.5 %) were complicated by PVST. The most common clinical presentations were abdominal pain (n = 9) and ascites (n = 5) but never any alarm symptoms. Other symptoms were vague and nonspecific (e.g., weight loss, fatigue, fever). Total pancreatectomy was a risk factor compared to hemipancreatectomy (p < 0.01), whereas the underlying disease per se did not make any difference. The median interval between surgery and diagnosis of PVST was 105 days (range 1-1,440 days). PVST was at least a contributing factor in the postoperative deaths of two patients. LMWH therapy did not significantly affect survival.

CONCLUSIONS

PVST remains a relatively infrequent complication after pancreatic resection. Because accurate diagnosis and timely intervention may reduce morbidity and mortality, the possibility of PVST should be considered in patients presenting with vague symptoms. Whether anticoagulant treatment is needed is still not clear; there were no obvious differences in outcome between treated and untreated patients.