Validation of the Khorana Venous Thromboembolism Risk Score in Japanese Cancer Patients

Risk assessment and prevention of cancer-associated venous thromboembolism in ambulatory patients with solid malignancies

Venous thromboembolism remains a major cause of morbidity and mortality among ambulatory cancer patients, necessitating effective risk assessment and prevention strategies. Despite the availability of risk assessment models and guidelines recommending primary thromboprophylaxis with low-molecular-weight heparins or direct oral anticoagulants, the application of these strategies is inconsistent. This review provides an overview of the current state-of-the-art venous thromboembolism risk assessment and thromboprophylaxis in ambulatory patients with cancer, focusing on existing risk assessment models and the latest guideline recommendations. Finally, it summarizes gaps in knowledge, discusses future directions, and highlights recent advances and state-of-the-art research presented at the 2024 International Society on Thrombosis and Haemostasis Congress in Bangkok, Thailand.

Incidence of venous thromboembolism and predictive ability of age-adjusted international prognostic index for prediction of venous thromboembolism in Asian patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is one of the malignancies at high risk for the development of venous thromboembolism (VTE). We aimed to evaluate the incidence of VTE and the predictive ability of the age-adjusted international prognostic index (aaIPI) for the prediction of VTE among DLBCL patients. This was a retrospective cohort study including adult patients with newly diagnosed DLBCL. Differences in VTE occurrence within one year after diagnosis of DLBCL were estimated across aaIPI groups using the Kaplan-Meier model, Cox's model, and Gray's model with deaths regarded as competing events. Five hundred and ninety-one newly diagnosed DLBCL patients with a median age of 58 (range 16-93) years were included in this study. At a median follow-up time of 365 (range 2-365) days, VTE events were objectively diagnosed in 32 patients, giving a one-year cumulative incidence of VTE of 5.4% (95% confidence interval [CI], 3.7-7.6). Patients with aaIPI ≥ 2 had a significantly higher risk of VTE than patients with aaIPI < 2 (hazard ratio, 3.5; 95% CI, 1.6-7.8; p = 0.001 based on Cox's model and sub-distribution hazard ratio, 3.0; 95% CI, 1.3-6.7; p = 0.007 using Gray's model). The C-statistic of aaIPI was 0.65 (95% CI, 0.58-0.72). We demonstrated that the incidence of VTE in Asian DLBCL patients was not uncommon. The aaIPI was effective in determining the risk of VTE in DLBCL patients, even when including death as a competing event. aaIPI may be helpful in identifying patients at higher risk of VTE in DLBCL patients.

Novel Insights in Venous Thromboembolism Risk Assessment Methods in Ambulatory Cancer Patients: From the Guidelines to Clinical Practice

Many cancer patients will experience venous thromboembolism (VTE) at some stage, with the highest rate in the initial period following diagnosis. Novel cancer therapies may further enhance the risk. VTE in a cancer setting is associated with poor prognostic, a decreased quality of life, and high healthcare costs. If thromboprophylaxis in hospitalized cancer patients and perioperative settings is widely accepted in clinical practice and supported by the guidelines, it is not the same situation in ambulatory cancer patient settings. The guidelines do not recommend primary thromboprophylaxis, except in high-risk cases. However, nowadays, risk stratification is still challenging, although many tools have been developed. The Khrorana score remains the most used method, but it has many limits. This narrative review aims to present the current relevant knowledge of VTE risk assessment in ambulatory cancer patients, starting from the guideline recommendations and continuing with the specific risk assessment methods and machine learning models approaches. Biomarkers, genetic, and clinical features were tested alone or in groups. Old and new models used in VTE risk assessment are exposed, underlining their clinical utility. Imaging and biomolecular approaches to VTE screening of outpatients with cancer are also presented, which could help clinical decisions.

Optimal D-Dimer Cutoff Values for Diagnosing Deep Vein Thrombosis in Patients with Comorbid Malignancies

BACKGROUND

Patients with malignancy are at high risk of venous thromboembolism, and early diagnosis is important. The Khorana score is known as a risk assessment for cancer-related thrombosis during chemotherapy, but there are still few reports on its diagnostic potential, the optimal D-dimer cutoff values for indications other than chemotherapy and the use of the Khorana score in combination with D-dimers. In this study, we examined the clinical appropriateness of increasing the D-dimer cutoff value.

METHODS

We retrospectively studied 208 malignancies out of 556 patients who underwent lower extremity venous ultrasonography at our hospital over a 2-year period from January 2018 to December 2019. The optimal D-dimer cutoff value for predicting deep vein thrombosis (DVT) in patients with malignancy was calculated by the Youden index. The usefulness of the Khorana score alone and the model combining the Khorana score with D-dimer for predicting DVT diagnosis was compared using receiver operating characteristic analysis.

RESULTS

Of 208 eligible patients, 59 (28.4%) had confirmed DVT. The optimal D-dimer cutoff value for predicting DVT comorbidity in patients with malignancy was 3.96 μg/mL. When the new D-dimer cutoff value was set at 4.0 μg/mL, the odds ratio (OR) for DVT diagnosis was 4.23 (95% confidence interval (CI) 2.10-8.55, P < 0.001), which was higher than the OR of 1.33 (95% CI: 0.98-1.81, P = 0.064) for the Khorana score. The area under the curve for the Khorana score and D-dimer was 0.714, which was significantly higher than the 0.611 for the Khorana score alone, with the difference being significantly higher at 0.103 (P = 0.004, 95% CI: 0.033-0.173).

CONCLUSIONS

The optimal D-dimer cutoff value for the diagnosis of DVT in patients with malignancy was 4.0 μg/mL. It was also suggested that the combination of the Khorana score with the D-dimer level was more accurate in diagnosing DVT than the Khorana score alone.

A Predictive Model for Cancer-Associated Thrombosis in Japanese Cancer Patients: Findings from the J-Khorana Registry

Background  Although the close relationship between cancer and venous thromboembolism (VTE) has been identified, risk stratification for VTE in Japanese patients with cancer remains unclear. Objectives  This study aimed to validate the Khorana VTE risk assessment score (KRS) for VTE diagnosis and establish an optimal predictive model for VTE in Japanese patients with cancer. Methods  A total of 7,955 Japanese patients with cancer were subdivided into low- (0), intermediate- (1-2), and high-score (3) groups according to the KRS. Using 37 explanatory variables, a total of 2,833 patients with cancer were divided into derivation and validation cohorts (5:5). A risk model for Japanese participants was developed using the derivation cohort data. Results  The prevalence of VTE in low-, intermediate-, and high-score patients was 1.2, 2.5, and 4.3%, respectively. Logistic regression analysis demonstrated that cancer stage (III-IV) and KRS ≥ 2 were independent and significant predictors of VTE onset. The risk model for VTE assigned 1 point to body mass index ≥25 kg/m 2 and 2 points each to the prevalence of osteochondral cancer and D-dimer level ≥1.47 µg/mL. The areas under the curve of the risk model were 0.763 and 0.656 in the derivation and validation cohorts, respectively. Conclusion  The KRS was useful in Japanese patients, and our new predictive model may be helpful for the diagnosis of VTE in Japanese patients with cancer.

Comparison of risk prediction scores for cancer-associated thrombosis in ambulatory cancer patients not receiving thromboprophylaxis: A prospective cohort study in a South-East Asian population

INTRODUCTION

To date, there is limited data regarding the incidence and risk prediction of cancer-associated thrombosis among South-East Asian patients who do not receive thromboprophylaxis.

MATERIALS AND METHODS

This was a prospective cohort study conducted at a tertiary medical center from June 2020 to December 2021 in Thailand. We enrolled cancer patients aged ≥ 18 years, with ECOG score ≤ 1, scheduled to receive the first cycle of chemotherapy. We measured incidence of venous thromboembolism (VTE), all-cause mortality and performance of risk prediction scores.

RESULTS

A total of 457 patients were included with a mean age of 58.18 ± 12.60 years. By the end of 6 months period, VTE had occurred in 30 patients (6.56 %, 95%CI 4.36-9.21). The median time to the first thrombosis was 1.94 months (IQR 0.26-3.19). Cancer associated thrombosis incidence was 14.58 % for Khorana score ≥ 3, 6.67 % for scores 1-2 and 2.13 % for score 0. C-statistics were 0.50 (95%CI 0.41-0.60) for Khorana score cut-off ≥ 2, 0.57 (95%CI 0.49-0.65) for Khorana score ≥ 3, 0.55 (95%CI 0.46-0.65) for PROTECHT score ≥ 3, and 0.57 (95%CI 0.49-0.65) for CONKO score ≥ 3. Classifying cholangiocarcinoma as very-high-risk increased the Khorana score cut-off ≥ 3's C-statistic to 0.62 (95%CI 0.53-0.71).

CONCLUSIONS

A significant proportion of ambulatory South-East Asian cancer patients without thromboprophylaxis developed VTE. Further prospective studies investigating the benefit of thromboprophylaxis in high-risk patients with active cancer are warranted.

Evaluating the effect of immune checkpoint inhibitors on venous thromboembolism in non-small cell lung cancer patients

OBJECTIVE

Currently, immune checkpoint inhibitors (ICIs) therapy is one of the main methods of treatment in non-small cell lung cancer (NSCLC). This study aimed to explore the risk factors of VTE and evaluate the effect of ICIs on VTE in patients with NSCLC.

RESEARCH DESIGN AND METHODS

We retrospectively studied patients with NSCLC who were divided into VTE group and without VTE (Non-VTE) group. We identified the risk factors of VTE in NSCLC patients and evaluated the effect of ICIs on VTE in NSCLC patients.

RESULTS

We found that clinical stage III-IV (P = 0.015) and Khorana score (KS) ≥ 2 (P = 0.047) were independent risk factors for the occurrence of VTE in NSCLC, and treatment with ICIs reduced the risk of VTE occurrence (P = 0.028). There were no differences of survival rates in the 12-month (P = 0.449), 24-month (P = 0.412), or 36-month (P = 0.315) between the VTE and non-VTE groups. History of anti-angiogenic therapy (P = 0.033) and chronic obstructive pulmonary disease (COPD) (P = 0.046) were independent risk factors for VTE in NSCLC patients who were treated with ICIs.

CONCLUSION

This study suggests that we should strengthen anticoagulant therapy when using ICIs for NSCLC patients with a history of anti-angiogenic therapy and COPD.

Application of the Khorana score for cancer-associated thrombosis prediction in patients of East Asian ethnicity undergoing ambulatory chemotherapy

BACKGROUND

The Khorana score (KS) has not been well studied in East Asian cancer patients, who have different genetic backgrounds for inherited thrombophilia, body metabolism, and cancer epidemiology.

METHODS

By using the Common Data Model, we retrospectively collected deidentified data from 11,714 consecutive newly diagnosed cancer patients who underwent first-line chemotherapy from December 2015 to December 2021 at a single institution in Korea, and we applied the KS for cancer-associated thrombosis (CAT) prediction. Age at diagnosis, sex, and use of highly thrombogenic chemotherapeutics were additionally investigated as potential risk factors for CAT development.

RESULTS

By 6 months after chemotherapy initiation, 207 patients (1.77%) experienced CAT. Only 0.4% had a body mass index (BMI) ≥ 35 kg/m² and changing the cutoff to 25 kg/m² improved the prediction of CAT. Age ≥ 65 years and the use of highly thrombogenic chemotherapeutics were independently associated with CAT development. KS values of 1 ~ 2 and ≥ 3 accounted for 52.3% and 7.6% of all patients, respectively, and the incidence of CAT in these groups was 2.16% and 4.16%, respectively, suggesting a lower incidence of CAT in the study population than in Westerners. The KS component regarding the site of cancer showed a good association with CAT development but needed some improvement.

CONCLUSION

The KS was partially validated to predict CAT in Korean cancer patients undergoing modern chemotherapy. Modifying the BMI cutoff, adding other risk variables, and refining the use of cancer-site data for CAT risk prediction may improve the performance of the KS for CAT prediction in East Asian patients.

Colonization of Fusobacterium nucleatum is an independent predictor of poor prognosis in gastric cancer patients with venous thromboembolism: a retrospective cohort study

BACKGROUND

Fusobacterium nucleatum (F. nucleatum) often colonizes cancerous gastric tissues and is characterized by the promotion of platelet aggregation and the development of visceral thrombosis. Venous thromboembolism (VTE) leads to a significant increase in the mortality of gastric cancer (GC) patients. However, the relationship between the colonization of F. nucleatum and the prognosis of GC patients is still unknown.

AIM

The aim of this study was to explore whether the colonization of F. nucleatum is related to the prognosis of GC patients complicated with VTE and to explore other potential risk factors.

METHODS

From 2017-2021, the data of 304 patients with new VTEs during the treatment of GC at the Affiliated Cancer Hospital of Zhengzhou University were collected. Fluorescence in situ hybridization of F. nucleatum was performed on pathological sections of cancer tissues from the patients. Survival analysis methods, including the Kaplan‒Meier method and Cox proportional hazard model, were performed.

RESULTS

F. nucleatum colonization was significantly associated with splanchnic vein thrombosis, higher platelet-lymphocyte ratio (PLR), and lower absolute lymphocyte count. In the multivariable Cox model, F. nucleatum colonization was found to be an independent risk factor for the prognosis of GC, with an adjusted HR of 1.77 (95% CI, 1.17 to 2.69 [P = 0.007]). In addition, patients with high PLR (HR: 2.65, P = 0.004) or VTE occurring during four cycles of chemotherapy (HR: 2.32, P = 0.012) exhibited shorter survival. Conversely, those experiencing VTE later (HR per month from diagnosis of GC: 0.95, P = 0.006) or using IVC filters (HR: 0.27, P = 0.011) had longer survival.

CONCLUSION

Colonization of F. nucleatum in GC tissues was associated with lower absolute lymphocyte count and higher PLR in GC patients with VTE. F. nucleatum colonization also appeared to be associated with the development of VTE in specific sites, in particular the splanchnic vein. Colonization of F. nucleatum may potentially represent an independent predictor of poor prognosis in GC patients. Additional research is necessary to validate these findings.

Identification of risk factors for venous thromboembolism and validation of the Khorana score in patients with advanced lung cancer: based on the multicenter, prospective Rising-VTE/NEJ037 study data

BACKGROUND

Management of cancer-associated venous thromboembolism (VTE) is essential in cancer treatment selection and prognosis. However, currently, no method exists for assessing VTE risk associated with advanced lung cancer. Therefore, we assessed VTE risk, including driver gene mutation, in advanced lung cancer and performed a Khorana score validation.

METHODS

The Rising-VTE/NEJ037 study was a multicenter prospective observational study that included patients with advanced lung cancer. In the Rising-VTE/NEJ037 study, the Khorana score was calculated for enrolled patients with available data on all Khorana score components. The modified Khorana score was based on the body mass index of ≥ 25 kg/m², according to the Japanese obesity standard. A multivariate logistic regression analysis, including patient background characteristics, was performed to evaluate the presence of VTE 2 years after the lung cancer diagnosis.

RESULTS

This study included 1008 patients with lung cancer, of whom 100 (9.9%) developed VTE. From the receiver operating characteristic curve analysis, VTE risk could not be determined because both the Khorana score (0.518) and modified Khorana score (0.516) showed very low areas under the curve. The risk factors for VTE in the multivariate analysis included female sex, adenocarcinoma, performance status, N factor, lymphocyte count, platelet count, prothrombin fragment 1 + 2 and diastolic blood pressure.

CONCLUSION

The Khorana score, which is widely used in cancer-VTE risk assessment, was less useful for Japanese patients with advanced lung cancer. Prothrombin fragment 1 + 2, a serum marker involved in coagulation, was more suitable for risk identification.

CLINICAL TRIAL INFORMATION

jRCTs061180025.