Incidental venous thromboembolism detected by PET-CT in patients with cancer: Prevalence and impact on survival rate

Prospective assessment of venous thromboembolism in lung cancer patients using a standardized screening protocol

Venous thromboembolism (VTE) is highly prevalent in cancer patients. While its actual incidence remains disparate among studies, specific subpopulations, such as lung cancer patients, might be at an increased risk. We aimed to assess the impact of a screening protocol in determining both the incidence and risk factors for VTE and evaluate the usefulness of predictive biomarkers and risk stratification tools in lung cancer patients. For this purpose, we designed a prospective cohort study including all consecutive, newly diagnosed lung cancer patients between October 2023 and April 2024 in a tertiary center and assessed each patient using a standardized screening protocol. VTE screening included baseline and 3-month reassessment of coagulation tests, D-dimer levels, and imaging (duplex ultrasound of the lower limbs for deep vein thrombosis screening and contrast-enhanced thoracic computed tomography for pulmonary embolism screening). A total of 102 patients were included, of which 16 (15.7%) were diagnosed with VTE. VTE was more frequent in males (p=0.031), patients with COPD (p=0.004), and patients with metastatic disease (p=0.038), particularly those under immunotherapy (p=0.026). Patients with VTE presented a D-dimer concentration more than three times higher at baseline and fivefold the levels observed in non-VTE patients at 3 months (p=0.002). Paired with Khorana scores, D-dimer concentration 4.5 mg/L at 3 months improved the predictive capacity of this VTE risk assessment tool in patients under active treatment. Active VTE screening yielded a significant increase in diagnosis, suggesting the incidence of this complication in newly diagnosed lung cancer patients is underestimated. Risk assessment tools can be enhanced by the addition of D-dimer-based parameters.

Incidental venous thrombosis in oncology in a sub-Saharan tertiary hospital

The relationship between cancer and thrombosis was initially highlighted in the 19th century. Vascular complications in oncology can be arterial or venous thrombosis, and incidental pulmonary embolism is a growing challenge. We aimed to describe the frequency and clinical characteristics of cancer patients with incidental venous thromboembolism (iVTE). We conducted a descriptive study at the Yaounde General Hospital. We included patients with a confirmed diagnosis of cancer, followed up on an outpatient basis, in whom an iVTE was identified on a computed tomography scan performed to evaluate tumour status over a 6-month period. Of the 359 patients, 19 had venous thromboses, representing a frequency of 5.3%. The mean age was 51.2 years. The sex ratio was 1.1 in favour of males. Comorbidities found were diabetes, hypertension and obesity. Colon cancer (5), ovarian cancer (3) and lung cancer (3) were the most frequent diagnoses. All patients had advanced disease with 14 (73.7%) being naive to anticancer treatment. Pulmonary arteries were the most affected vessel (63.1%). The frequency of iVTE in a sub-Saharan context was around 5%.

Pulmonary Embolism in the Cancer Associated Thrombosis Landscape

In cancer patients, pulmonary embolism (PE) is the second leading cause of death after the cancer itself, most likely because of difficulties in diagnosing the disease due to its nonclassical presentation. The risk of PE recurrence and possibly the case-fatality rate depends on whether the patient presents a symptomatic PE, an unsuspected PE, a subsegmental PE, or a catheter-related PE. Choosing the best therapeutic option is challenging and should consider the risk of both the recurrence of thrombosis and the occurrence of bleeding. The purpose of this review is to provide an overview of the clinical characteristics and the treatment of cancer-associated PE, which could benefit clinicians to better manage the deadliest form of thrombosis associated with cancer. After a brief presentation of the epidemiological data, we will present the current attitude towards the diagnosis and the management of cancer patients with PE. Finally, we will discuss the perspectives of how the medical community can improve the management of this severe medical condition.

Feasibility and impact of screening for venous thromboembolism in treatment-naive lung cancer patients-Results of a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) in cancer remains underdiagnosed. This prospective study aimed to evaluate the feasibility of screening for VTE in lung cancer (LC) patients. We assess the incidence of VTE, its risk factors, and effects on overall survival (OS).

METHODS

Consecutive treatment-naive LC patients were screened for deep venous thrombosis (DVT) with compression ultrasonography and pulmonary thromboembolism (PTE) with computed tomography pulmonary angiography (CTPA) at diagnosis and after 3 months of treatment. The incidence rate of VTE (DVT and/or PTE) was calculated. Risk factors associated with VTE were assessed using logistic regression analysis. All participants were followed-up to 1 year after enrollment. OS was compared in LC subjects with and without VTE, using the Cox proportional hazard analysis.

RESULTS

Around 301 subjects with LC (stages IIIB-IV accounted for 83.1%) were enrolled, of which 16 had VTE (5.3%). The incidence rate of VTE was 90 per 1000 person-years (PY). PTE was asymptomatic in 27.3% of cases while all DVT episodes were symptomatic. The incidence rate of asymptomatic PTE identified during the screening was 17 per 1000 PY. The median duration from LC diagnosis to the VTE event was 96.5 days. Median OS was significantly less in VTE patients [161 versus 311 days; P = 0.007] and death was attributable to VTE in 50%. After adjusting for covariates, VTE (hazard ratio [HR] = 2.1), smoking (HR = 1.7), and Eastern cooperative oncology group performance status ≥2 (HR = 1.6) were independently associated with poor OS in LC.

CONCLUSIONS

VTE occurs in approximately 1 in 20 newly-diagnosed patients with LC and is associated with decreased OS. Screening for PTE may be considered even in resource-limited settings.

Concurrence of Gastric Cancer and Incidental Pulmonary Embolism May Be a Prognostic Factor for Advanced Gastric Cancer Patients with Incidental Pulmonary Embolism

Objective

Cancer is well known as the most important risk factor for the emergence of pulmonary embolism (PE). The incidence of incidental PE (IPE) has increased with widely use of multi-detector-row computed tomography (CT) technology. Simultaneously, more new cancer patients diagnosed concomitantly with IPE are found. No study has examined the presentation and prognosis of incidental pulmonary embolism (IPE) in gastric cancer patients. The aim of this study was to analyse prognostic factors in patients with advanced gastric cancer complicated with IPE.

Patients and Methods

Ninety patients with histologically confirmed advanced gastric adenocarcinoma diagnosed with IPE were enrolled. Continuous variables were compared using Student’s t-test or the Mann–Whitney U-test if non-normally distributed. The Chi-squared test (or Fisher’s exact test where appropriate) was used to compare categorical variables. The Kaplan–Meier method and the Log rank test were used for survival analysis. Independent prognostic factors for survival were determined using a Cox proportional hazards model. A two-sided P-value < 0.05 was considered statistically significant.

Results

Nineteen patients were diagnosed with IPE concomitantly with gastric cancer. Concurrence of gastric cancer and IPE, lack of anticoagulation therapy, and location of IPE were associated with survival. After adjusting for age and sex, the concurrence of gastric cancer and IPE, lack of anticoagulation, and central IPE independently influenced the survival of advanced gastric cancer patients with IPE. Subgroup analysis of patients with peripheral pulmonary embolisms confirmed that anticoagulant therapy provided a survival benefit.

Conclusion

Concurrence of gastric cancer and IPE may be a prognostic factor for advanced gastric cancer patients with IPE.

Apixaban for the prevention of venous thromboembolism in high-risk ambulatory cancer patients receiving chemotherapy: Rational and design of the AVERT trial

Patients with active cancer have a heightened risk of venous thromboembolism (VTE). This risk is further increased by the initiation of chemotherapy. Although previous studies have suggested that the use of parenteral thromboprophylaxis in all ambulatory cancer patients receiving chemotherapy significantly decreases the rate of VTE, current clinical practice guidelines do not recommend routine use of thromboprophylaxis in this patient population. A major criticism of these studies has been the inclusion of patients at lower risk for VTE, which may have diluted the potential beneficial effect of the parenteral thromboprophylaxis. It is therefore imperative to appropriately risk stratify ambulatory cancer patients using a validated scoring system (e.g. Khorana risk score) in order to identify those most likely to benefit from thromboprophylaxis. Direct oral anticoagulants, such as apixaban, may offer a convenient and safe option for thromboprophylaxis. As such, AVERT will randomize 574 ambulatory cancer patients receiving chemotherapy who are at high-risk for VTE (as defined by a Khorana score of ≥2) to Apixaban 2.5 mg BID versus placebo. The primary study outcome will be the first episode of objectively documented symptomatic or incidental VTE (deep vein thrombosis and/or pulmonary embolism) within the first 6 months (180 days ± 3) following initiation of the blinded study drug for both intervention and placebo groups. The secondary safety outcomes include major bleeding, clinically relevant non-major bleeding, and overall survival rates. This study will hopefully offer evidence regarding the benefit of apixaban in ambulatory patients at high risk for VTE receiving chemotherapy.

Incidental venous thromboembolism: is anticoagulation indicated?

Patients with cancer have a high risk of venous thromboembolism (VTE) and about one-half of these events are incidentally detected. The prognosis of incidental VTE appears to be similar to symptomatic events, with comparably high rates of recurrent VTE in this patient population. In the absence of major contraindications, anticoagulant treatment with low-molecular-weight heparin for 3 to 6 months is generally recommended for incidental proximal deep vein thrombosis as well as for incidental pulmonary embolism that involves multiple subsegmental or more proximal pulmonary arteries. The decision of whether to extend treatment beyond 3 to 6 months should be evaluated on a case-by-case basis after periodic reassessment of the risks factors for bleeding and recurrent VTE while also taking into account patient preferences. The clinical relevance of a single incidental subsegmental pulmonary embolism without concomitant deep vein thrombosis is uncertain and either a watchful approach or a shorter course of anticoagulation to minimize the bleeding risk may also be considered. Preliminary evidence suggests that anticoagulation treatment may be beneficial for cancer patients with incidental distal deep vein thrombosis or incidental splanchnic vein thrombosis.

Management of incidental pulmonary embolism

Incidental pulmonary embolism (PE) is a frequent finding on routine computed tomography (CT) scans of the chest, occurring in 1.1% of coronary CT scans and 3.6% of oncological CT scans. Despite this high frequency, optimal management of incidental PE has not been addressed in clinical trials and remains the subject of debate. Although these CT scans have not been performed with a dedicated PE protocol and have suboptimal contrast enhancement, diagnosis of incidental PE has been shown to be accurate up to the segmental and subsegmental arteries. The embolic load in incidental PE is lower than that in symptomatic PE. Even so, observational studies suggest that the natural course of incidental PE is similar to that of symptomatic PE with regard to the risk of recurrent venous thrombotic disease and mortality. Interestingly, the increased use of more advanced CT technology has coincided with an increase in the rate of incidental subsegmental PE, as is the case for symptomatic subsegmental PE. Although clinical trials are lacking, and observational data are limited to cancer-associated incidental PE, the consensus is that the management of incidental PE is identical to that of symptomatic PE, including the choice of optimal drug class, outpatient treatment and total duration of treatment.

Clinically Relevant Cardiovascular Findings Detected on Staging Computed Tomography in Patients with Several Malignancies

We evaluated the frequency and subtypes of clinically relevant cardiovascular (CV) findings identified on staging computed tomography (CT) in a large sample. Patients (n = 5026) with different malignant diseases were staged by CT. Clinically relevant CV findings (CRCFs) were included into the study. The CRCFs were defined as cardiac aneurysm, cardiac thrombus, venous thrombosis, arterial thrombosis, arterial dissection, pulmonary thromboembolism, arterial dissection, and dislocation of venous ports/central venous catheters. The CRCFs were identified in 342 patients (6.8% of all patients). Overall, 491 CRCFs were identified in the patients (1.4 per patient). In 203 (59.4%) patients, 1 CRCF; in 129, 2 (37.7%) CRCFs; and in 10 (2.9%) cases, 3 CRCFs were detected. There were incidental venous thrombosis (n = 298, 60.7% of all CRCFs), pulmonary thromboembolism (n = 84, 17.1%), arterial aneurysms (n = 44, 8.9%), arterial thrombosis (n = 43, 8.8%), heart thrombus (n = 15, 3.1%), arterial dissection (n = 3, 0.6%), heart aneurysms (n = 2, 0.4%), and port catheter dislocation (n = 2, 0.4%). The identified CRCF can be associated with potential hazardous complications. The CV system should be carefully evaluated in staging CT investigations.

Venous thromboembolism and lung cancer: a review

Venous thromboembolism (VTE) is a common complication of malignancies and epidemiological studies suggest that lung cancer belonged to the group of malignancies with the highest incidence rates of VTE. Risk factors for VTE in lung cancer patients are adenocarcinoma, NSCLC in comparison with SCLC, advanced disease, pneumonectomy, chemotherapy including antiangiogenic therapy. Other risk factors are pretreatment platelet counts and increased release of TF-positive microparticles. Elevated D-dimer levels do not necessarily indicate an increased risk of VTE but have been shown to be predictive for a worse clinical outcome in lung cancer patients. Mechanisms responsible for the increase in venous thrombosis in patients with lung cancer are not understood.

Currently no biomarker is recognized as a predictor for VTE in lung cancer patients.

Although several clinical trials have reported the efficacy of antithrombotic prophylaxis in patients with lung cancer who are receiving chemotherapy, further trials are needed to assess the clinical benefit since these patients are at an increased risk of developing a thromboembolism.