Predictors of active cancer thromboembolic outcomes: validation of the Khorana score among patients with lung cancer

Evaluation of risk factors and assessment models for predicting venous thromboembolism in lung cancer patients

The aim of the study was to investigate the prognostic significance of selected risk assessment models (RAMs) for predicting venous thromboembolism (VTE) events in patients undergoing outpatient chemotherapy for lung cancer. We evaluated the following VTE-risk assessment tools: Khorana risk score (KRS), PROTECHT score, CONKO score and COMPASS-cancer-associated thrombosis score (COMPASS-CAT). Retrospective analyses were performed on 118 patients with lung cancer, 20 of whom developed VTE with a median of 2.5 months from diagnosis. Patients receiving gemcitabine-based regimen (25%), patients with a history of atrial fibrillation (AF) and patients with chronic kidney disease developed VTE more often than other patients. In the multivariate analysis, high COMPASS-CAT score (OR 8.73; 95% CI 1.01–75.22, P = 0.049), gemcitabine chemotherapy (OR 3.37; 95% CI 1.09–10.39, P = 0.035) and AF (OR 7.19; 95% CI 1.89–27.33, P = 0.004) were all significantly associated with VTE development. VTE occurred in; 13% (n = 2) of the KRS high-risk group, 17.7% (n = 11) of the PROTECHT high-risk group, 15% (n = 4) of the CONKO high-risk group and 23.8% (n = 20) of the COMPASS-CAT high-risk group (n = 84). Only the COMPASS-CAT score was able to identify 100% of patients who developed VTE, and best discriminated between patients with high and low risk of VTE development (C statistic 0.89). The ROC analysis indicated a cutoff value of 11 points (95% CI 0.821–0.962) for COMPASS-CAT for VTE development in patients with lung cancer. In conclusion, in our study of all the VTE–RAMs analyzed, the COMPASS-CAT model was the most accurate predictor of VTE development in patients with lung cancer.

Prediction of venous thromboembolism in newly diagnosed patients treated for lymphoid malignancies: validation of the Khorana Risk Score

The utility of the venous thromboembolism (VTE) risk assessment model known as the Khorana Risk Score (KRS) in patients with lymphoid malignancies receiving outpatient chemotherapy is not defined. We evaluated the association of the KRS with VTE in patients treated for diffuse large B cell lymphoma (DLBCL) or Hodgkin lymphoma (HL). Retrospective analyses were performed in 428 patients, 241 of whom were newly diagnosed with DLBCL and 187 of whom had HL. During the initial therapy, 64 (15%) patients developed VTE and 56 died during follow-up. More VTE events occurred in patients with DLBCL than in patients with HL. According to the KRS, 364 (85%) and 64 (15%) patients were considered to be at intermediate risk and high risk of VTE development, respectively. The high-risk KRS patients were more often diagnosed with HL than DLBCL (19 vs. 10%, P = 0.0143). The KRS did not discriminate between high- and intermediate-risk patients with respect to VTE occurrence (17 vs. 15%, P = 0.5868). In our patients, the KRS did not adequately predict VTE (positive predictive value 15%, negative predictive value 82% and C statistic 0.51). In the multivariate analysis, bulky disease (OR 2.34; 95% CI 1.62-3.36, P < 0.0001), poor prognostic disease (OR 1.32; 95% CI 1.01-1.74, P = 0.049) and DLBCL histological subtype (OR 1.61; 95% CI 1.17-2.19, P = 0.003) were all significantly associated with the VTE development. In this cohort of patients with lymphoid malignancies, the KRS did not adequately stratify or predict VTE events in patients at a higher risk of VTE. This finding suggests the need for the development of a disease-specific VTE assessment model.

Predictors of Venous Thromboembolism and Early Mortality in Lung Cancer: Results from a Global Prospective Study (CANTARISK)

BACKGROUND

Patients with lung cancer are known to be at increased risk for venous thromboembolism (VTE). Venous thromboembolism is associated with increased risk for early mortality. However, there have been no studies performing a comprehensive assessment of risk factors for VTE or early mortality in lung cancer patients undergoing systemic chemotherapy in a global real-world setting.

MATERIALS AND METHODS

CANTARISK is a prospective, global, noninterventional cohort study including patients with lung cancer initiating a new cancer therapy. Clinical data were collected until 6-month follow-up. The impact of patient-, disease-, and treatment-related factors on the occurrence of VTE and early mortality was evaluated in univariable and multivariable Cox regression analyses. A previously validated VTE risk score (VTE-RS) was also calculated (also known as Khorana score).

RESULTS

Of 1,980 patients with lung cancer who were enrolled from 2011 to 2012, 84% had non-small cell lung cancer. During the first 6 months, 121 patients developed a VTE (6.1%), of which 47% had pulmonary embolism, 46% deep vein thrombosis, 3% catheter-associated thrombosis, and 4% visceral thrombosis. Independent predictors for VTE included female sex, North America location, leg immobilization, and presence of a central venous catheter. The VTE-RS was not significantly associated with VTE in either univariable or multivariable analysis in this population. During the study period, 472 patients died, representing 20%, 24%, 36%, and 25% with VTE-RS 1, 2, ≥3, or unknown, respectively (p < .0001). Significant independent predictors of early mortality include older age, current/former smoking, chronic obstructive pulmonary disease, Eastern Cooperative Oncology Group performance status ≥2, no prior surgery, and metastatic disease, as well as the VTE-RS.

CONCLUSION

In this global, prospective, real-world analysis, several demographic, geographic, and clinical factors are independent risk factors for VTE and early mortality in patients with lung cancer. The VTE-RS represents a significant independent predictor of early mortality but not for VTE in lung cancer in the era of targeted therapy.

IMPLICATIONS FOR PRACTICE

Multiple risk factors for both venous thromboembolism (VTE) and early mortality in patients with lung cancer receiving systemic chemotherapy should guide best practice by better informing clinical evaluation and treatment decision-making. The Khorana risk score is of value in assessing the risk of early all-cause mortality along with other clinical parameters in patients with lung cancer receiving systemic therapy. Further study is needed to fully evaluate the validity of the risk score in predicting the risk of VTE in the modern era of lung cancer therapy.

Validation of a Machine Learning Approach for Venous Thromboembolism Risk Prediction in Oncology

Using kernel machine learning (ML) and random optimization (RO) techniques, we recently developed a set of venous thromboembolism (VTE) risk predictors, which could be useful to devise a web interface for VTE risk stratification in chemotherapy-treated cancer patients. This study was designed to validate a model incorporating the two best predictors and to compare their combined performance with that of the currently recommended Khorana score (KS). Age, sex, tumor site/stage, hematological attributes, blood lipids, glycemic indexes, liver and kidney function, BMI, performance status, and supportive and anticancer drugs of 608 cancer outpatients were all entered in the model, with numerical attributes analyzed as continuous values. VTE rate was 7.1%. The VTE risk prediction performance of the combined model resulted in 2.30 positive likelihood ratio (+LR), 0.46 negative LR (−LR), and 4.88 HR (95% CI: 2.54–9.37), with a significant improvement over the KS [HR 1.73 (95% CI: 0.47–6.37)]. These results confirm that a ML approach might be of clinical value for VTE risk stratification in chemotherapy-treated cancer outpatients and suggest that the ML-RO model proposed could be useful to design a web service able to provide physicians with a graphical interface helping in the critical phase of decision making.

Performance of Current Thromboembolism Risk Assessment Tools in Patients With Gastric Cancer and Validity After First Treatment

Patients with gastric cancer (GC) are at higher risk of thromboembolism when compared to other solid tumors. We aim to determine the predictive performance of current venous thromboembolism (VTE) predictive tools and their variability and validity after first treatment. Single institution cohort of GC-treated patients (2010*15). We abstracted predictive tools, validated for VTE prediction in patient with cancer; including the Khorana Score (KRS), platelet to lymphocyte ratio (PLR), and neutrophil to lymphocyte ratio (NLR). The primary outcome was CAT prediction. We included 112 patients who were predominantly men (66%), 58 (51-64)-year-olds, with adenocarcinoma (84%) and advanced disease (59%). The median follow-up was 21.3 months (9.5-42.6). The VTE occurrence was 12%. The median time from diagnosis to VTE occurrence was 59 days (36-258). In our cohort, performance status (PS; hazard ratio [HR], 8.02; 95% confidence interval [CI], 2.37-27.14; P < .01) was an independent predictor of VTE whereas KRS (univariate HR, 2.3; 95% CI, 0.7-7.4; P = .17), PLR (univariate HR, 0.8; 95% CI, 0.2-3.1; P = .8), and NLR (univariate HR, 0.8; 95% CI, 0.3-2.5; P = .8) at baseline were not associated with VTE risk. The posttreatment KRS was an independent predictor of VTE (HR, 3.69; 95% CI, 1.17-11.65; P = .25) along with PS (HR, 7.58; 95% CI, 2.27-25.33; P = .01). Posttreatment KRS appears as a valid tool to identify patients with GC at high risk of VTE after first cancer treatment.

Comparison of risk prediction scores for venous thromboembolism in cancer patients: a prospective cohort study

In ambulatory patients with solid cancer, routine thromboprophylaxis to prevent venous thromboembolism is not recommended. Several risk prediction scores to identify cancer patients at high risk of venous thromboembolism have been proposed, but their clinical usefulness remains a matter of debate. We evaluated and directly compared the performance of the Khorana, Vienna, PROTECHT, and CONKO scores in a multinational, prospective cohort study. Patients with advanced cancer were eligible if they were due to undergo chemotherapy or had started chemotherapy in the previous three months. The primary outcome was objectively confirmed symptomatic or incidental deep vein thrombosis or pulmonary embolism during a 6-month follow-up period. A total of 876 patients were enrolled, of whom 260 (30%) had not yet received chemotherapy. Fifty-three patients (6.1%) developed venous thromboembolism. The c-statistics of the scores ranged from 0.50 to 0.57. At the conventional positivity threshold of 3 points, the scores classified 13-34% of patients as high-risk; the 6-month incidence of venous thromboembolism in these patients ranged from 6.5% (95%CI: 2.8-12) for the Khorana score to 9.6% (95%CI: 6.6-13) for the PROTECHT score. High-risk patients had a significantly increased risk of venous thromboembolism when using the Vienna (subhazard ratio 1.7; 95%CI: 1.0-3.1) or PROTECHT (subhazard ratio 2.1; 95%CI: 1.2-3.6) scores. In conclusion, the prediction scores performed poorly in predicting venous thromboembolism in cancer patients. The Vienna CATS and PROTECHT scores appear to discriminate better between low- and high-risk patients, but further improvements are needed before they can be considered for introduction into clinical practice.

Clinical significance of glycemic parameters on venous thromboembolism risk prediction in gastrointestinal cancer

AIM

To investigate the possible predictive role of routinely used glycemic parameters for a first venous thromboembolism (VTE) episode in gastrointestinal (GI) cancer ambulatory patients - with or without clinically diagnosed type 2 diabetes (T2D) or obesity - treated with chemotherapy.

METHODS

Pre-treatment fasting blood glucose, insulin, glycated hemoglobin (HbA_1c) and homeostasis model of risk assessment (HOMA) were retrospectively evaluated in a cohort study of 342 GI cancer patients. Surgery was performed in 142 (42%) patients with primary cancer, 30 (21%) and 112 (79%) of whom received neoadjuvant and adjuvant therapies, respectively. First-line chemotherapy was administered in 200 (58%) patients with metastatic disease. The study outcome was defined as the occurrence of a first symptomatic or asymptomatic VTE episode during active treatment.

RESULTS

Impaired glucose tolerance (IGT) or T2D were diagnosed in 30% of GI cancer patients, while overweight/obesity had an incidence of 41%. VTE occurred in 9.4% of patients (7% of non-diabetic non-obese), especially in those with a high ECOG score (P = 0.025). No significant association was found between VTE incidence and T2D, obesity, different tumor types, metastatic disease, Khorana class of risk, or different anti-cancer drugs, although VTE rates were substantially higher in patients receiving bevacizumab (17% vs 8%, P = 0.044). Conversely, all glucose metabolic indexes were associated with increased VTE risk at ROC analysis. Multivariate Cox proportional analyses confirmed that HOMA index (HR = 4.13, 95%CI: 1.63-10.5) or fasting blood glucose (HR = 3.56, 95%CI: 1.51-8.39) were independent predictors of VTE occurrence during chemotherapy.

CONCLUSION

The results here reported demonstrate that evaluating glucose metabolic asset may allow for VTE risk stratification in GI cancer, helping to identify chemotherapy-treated patients who might benefit from thromboprophylaxis. Further multicenter prospective studies involving a larger number of patients are presently needed.

A Predictive Score for Thrombosis Associated with Breast, Colorectal, Lung, or Ovarian Cancer: The Prospective COMPASS-Cancer-Associated Thrombosis Study

The COMPASS‐CAT study was undertaken in outpatients with breast, colon, lung, or ovarian cancer. The aim of the study was to identify the most relevat risk factors for symptomatic thromboembolism and to develop a risk assessment model applicable to patients after the initiation of anticancer treatment.

Background.

The stratification of outpatients on chemotherapy for breast, colorectal, lung, and ovarian cancers at risk of venous thromboembolism (VTE) remains an unmet clinical need. The derivation of a risk assessment model (RAM) for VTE in these patients was the aim of the study “Prospective Comparison of Methods for thromboembolic risk assessment with clinical Perceptions and AwareneSS in real life patients–Cancer Associated Thrombosis” (COMPASS–CAT).

Patients and Methods.

The derivation cohort consisted of 1,023 outpatients. Patients on low molecular weight heparin (LMWH) thromboprophylaxis were excluded. Documented symptomatic VTE was the endpoint of the study.

Results.

Patients had breast (61%), colorectal (17%), lung (13%), or ovarian cancer (8.6%) at localized (30%) or advanced stage (70%). In 64% of patients, cancer was diagnosed within the last 6 months prior to inclusion. Most of them were on chemotherapy when assessed. Symptomatic VTE occurred in 8.5% of patients. The COMPASS–CAT RAM includes the following variables: (a) anthracycline or anti‐hormonal therapy, (b) time since cancer diagnosis, (c) central venous catheter, (d) stage of cancer, (e) presence of cardiovascular risk factors, (f) recent hospitalization for acute medical illness, (g) personal history of VTE, and (h) platelet count. At 6 months, patients stratified at low/intermediate and high‐risk groups had VTE rates of 1.7% and 13.3%, respectively. The area under the curve of receiver operating characteristics analysis was 0.85. The sensitivity and specificity of the RAM were 88% and 52%, respectively. The negative and positive predictive values of the RAM were 98% and 13%, respectively.

Conclusion.

The COMPASS–CAT RAM includes reliable and easily collected VTE risk predictors and, in contrast to the Khorana score, it is applicable after the initiation of anticancer treatment in patients with common solid tumors. Its robustness for stratification of patients at high and low/intermediate VTE risk needs to be externally validated.

Implications for Practice.

The Prospective Comparison of Methods for thromboembolic risk assessment with clinical Perceptions and AwareneSS in real life patients–Cancer Associated Thrombosis (COMPASS–CAT) study provides a new risk assessment model (RAM) for venous thromboembolism (VTE) applicable in outpatients with breast, colorectal, lung or ovarian cancer. The COMPASS–CAT RAM is robust, applicable during chemotherapy and determines the need for VTE prévention by including reliable and easily collected VTE predictors associated with cancer status, its treatment as well as with patients' characteristics and comorbidities. An independent external validation of the RAM is indicated before its use in clinical practice.

Performance of Khorana Risk Score for Prediction of Venous Thromboembolism in Patients With Hepatocellular Carcinoma

Cancer-associated venous thromboembolism (VTE) is one of the leading causes of mortality and morbidity among patients with malignancy. The Khorana risk score (KRS) is currently the best validated risk assessment model to stratify risks of VTE development in ambulatory patients with cancer. In the current study, we assessed the performance of KRS in patients with hepatocellular carcinoma (HCC). We retrospectively analyzed patients with diagnosis of HCC (screened by International Classification of Diseases [ ICD-9] and ICD-10 code, confirmed with radiographic examination and/or histopathology) at a large public hospital over 15 years (January 2000 through July 2015). Cases with VTE were identified through radiographic examination and blindly adjudicated. Khorana risk score was calculated for each patient, and its association with VTE development and mortality was assessed. Among 270 patients with HCC, 16 (5.9%) cases of VTE were identified, including 7 (43.8%) pulmonary embolism, 4 (25%) peripheral deep vein thrombosis, and 6 (37.5%) intra-abdominal thrombosis. One hundred eighty-four (68.1%) patients had a KRS of 0 and 86 (31.9%) patients had a KRS >0. Most of the thrombotic (n = 9, 56%) events occurred in the low-risk group. In univariate analysis, only prechemotherapy leukocyte count equal to or greater than 11 000/μL was statistically significant in the prediction of VTE incidence. After adjusting for confounding factors in multivariate analysis, KRS >0 was not predictive of VTE (hazard ratio [HR] = 1.83, 95% confidence interval [CI] = 0.81-4.15, P = .15) or mortality (HR = 1.61, 95% CI = 0.92-2.81, P = .09). Khorana risk score did not predict VTE development or mortality in patients with HCC. Design of HCC-specific risk assessment model for VTE development is necessary.

Predictors of active cancer thromboembolic outcomes. RIETE experience of the Khorana score in cancer-associated thrombosis

Even though the Khorana risk score (KRS) has been validated to predict against the development of VTE among patients with cancer, it has a low positive predictive value. It is also unknown whether the score predicts outcomes in patients with cancer with established VTE. We selected a cohort of patients with active cancer from the RIETE (Registro Informatizado Enfermedad TromboEmbolica) registry to assess the prognostic value of the KRS at inception in predicting the likelihood of VTE recurrences, major bleeding and mortality during the course of anticoagulant therapy. We analysed 7948 consecutive patients with cancer-associated VTE. Of these, 2253 (28 %) scored 0 points, 4550 (57 %) 1-2 points and 1145 (14 %) scored ≥3 points. During the course of anticoagulation, amongst patient with low, moderate and high risk KRS, the rate of VTE recurrences was of 6.21 (95 %CI: 4.99-7.63), 11.2 (95 %CI: 9.91-12.7) and 19.4 (95 %CI: 15.4-24.1) events per 100 patient-years; the rate of major bleeding of 5.24 (95 %CI: 4.13-6.56), 10.3 (95 %CI: 9.02-11.7) and 19.4 (95 %CI: 15.4-24.1) bleeds per 100 patient-years and the mortality rate of 25.3 (95 %CI: 22.8-28.0), 58.5 (95 %CI: 55.5-61.7) and 120 (95 %CI: 110-131) deaths per 100 patient-years, respectively. The C-statistic was 0.53 (0.50-0.56) for recurrent VTE, 0.56 (95 %CI: 0.54-0.59) for major bleeding and 0.54 (95 %CI: 0.52-0.56) for death. In conclusion, most VTEs occur in patients with low or moderate risk scores. The KRS did not accurately predict VTE recurrence, major bleeding, or mortality among patients with cancer-associated thrombosis.