Incidence of and risk factors for preoperative deep venous thrombosis in patients undergoing gastric cancer surgery

Machine learning assisted radiomics in predicting postoperative occurrence of deep venous thrombosis in patients with gastric cancer

BACKGROUND

Gastric cancer patients are prone to lower extremity deep vein thrombosis (DVT) after surgery, which is an important cause of death in postoperative patients. Therefore, it is particularly important to find a suitable way to predict the risk of postoperative occurrence of DVT in GC patients. This study aims to explore the effectiveness of using machine learning (ML) assisted radiomics to build imaging models for prediction of lower extremity DVT occurrence in GC patients after surgery.

METHODS

Included in this retrospective study were eligible patients who underwent surgery for GC. CT imaging data from these patients were collected and divided into a training set and a validation set. The least absolute shrinkage and selection operator (LASSO) algorithm was applied to reduce the dimensionality of variables in the training set. Four machine learning algorithms, known as random forest (RF), extreme gradient boosting (XGBoost), support vector machine (SVM) and naive Bayes (NB), were used to develop models for predicting the risk of lower extremity DVT occurrence in GC patients. These models were subsequently validated using the internal validation set and an external validation cohort.

RESULTS

LASSO analysis identified 10 variables, based on which four ML models were established, which were then incorporated with the clinical characteristics to predict lower extremity DVT occurrence in the training set. Among these models, RF and NB demonstrated the highest predictive performance, achieving an AUC of 0.928, while SVM and XGBoost achieved a slightly lower AUC of 0.915 and 0.869, respectively.

CONCLUSION

ML algorithms based on imaging information may prove to be novel non-invasive models for predicting postoperative occurrence of DVT in GC patients.

Increased cardiovascular disease risk among adolescents and young adults with gastric cancer

BACKGROUND

Previous studies have investigated cardiovascular disease (CVD) risks in cancer patients, but there is limited knowledge concerning the CVD risk in adult and young adolescent (AYA) survivors of gastric cancer.

OBJECTIVES

This study aims to investigate the incidence of CVD in AYA gastric cancer survivors, analyzing it by treatment type and identifying associated risk factors.

METHODS

We conducted a retrospective cohort study using Korean National Health Insurance Service data collected from 2006 to 2019. Propensity score matching (1:3, caliper < 0.1) was performed using the variables age, sex, income, residential area, and presence of comorbidities, and we classified participants into gastric cancer (n = 6562) and non-cancer control (n = 19,678) groups. Cox regression models were used to calculate hazard ratios (HRs) for CVD incidence. The study assessed CVD incidence by cancer treatment and identified risk factors through multivariable Cox regression.

RESULTS

During a median 6.5-year follow-up, AYA gastric cancer survivors consistently exhibited greater CVD incidence. Their risk of CVD was significantly elevated compared to that of controls (HR, 1.18; 95% confidence interval [CI] 1.05-1.33). In particular, deep vein thrombosis (HR, 3.93; 95% CI 3.06-14.67) and pulmonary embolism (HR, 6.58; 95% CI 3.06-14.67) risks were notably increased. Chemotherapy was associated with an increased risk of stroke, heart failure, atrial fibrillation, deep vein thrombosis, and pulmonary embolism. Hypertension (HR, 1.58; 95% CI 1.10-2.26) and dyslipidemia (HR, 1.46; 95% CI 1.06-2.20) emerged as risk factors for CVD development.

CONCLUSION

This study reports elevated risks of CVD in AYA gastric cancer survivors and emphasizes the need for vigilant monitoring of CVD in this population.

Development and validation of a multi-parameter nomogram for venous thromboembolism in gastric cancer patients: a retrospective analysis

OBJECTIVE

Gastric cancer (GC), one of the highest venous thromboembolism (VTE) incidence rates in cancer, contributes to considerable morbidity, mortality, and, prominently, extra cost. However, up to now, there is not a high-quality VTE model to steadily predict the risk for VTE in China. Consequently, setting up a prediction model to predict the VTE risk is imperative.

METHODS

Data from 3,092 patients from December 15, 2017, to December 31, 2022, were retrospectively analyzed. Multiple logistic regression analysis was performed to assess risk factors for GC, and a nomogram was constructed based on screened risk factors. A receiver operating curve (ROC) and calibration plot was created to evaluate the accuracy of the nomogram.

RESULTS

The risk factors of suffering from VTE were older age (OR = 1.02, 95% CI [1.00-1.04]), Karnofsky Performance Status (KPS) ≥ 70 (OR = 0.45, 95% CI [0.25-0.83]), Blood transfusion (OR = 2.37, 95% CI [1.47-3.84]), advanced clinical stage (OR = 3.98, 95% CI [1.59-9.99]), central venous catheterization (CVC) (OR = 4.27, 95% CI [2.03-8.99]), operation (OR = 2.72, 95% CI [1.55-4.77]), fibrinogen degradation product (FDP) >5 µg/mL (OR = 1.92, 95% CI [1.13-3.25]), and D-dimer > 0.5 mg/L (OR = 2.50, 95% CI [1.19-5.28]). The area under the ROC curve (AUC) was 0.82 in the training set and 0.85 in the validation set.

CONCLUSION

Our prediction model can accurately predict the risk of the appearance of VTE in gastric cancer patients and can be used as a robust and efficient tool for evaluating the possibility of VTE.

Preoperative and postoperative clinical signatures of postgastrectomy venous thromboembolism (VTE) in patients with gastric cancer: A retrospective cohort study

BACKGROUND

This study aimed to identify preoperative and postoperative risk factors of venous thromboembolism (VTE) after gastrectomy in gastric cancer (GC) patients.

METHODS

757 GC patients underwent gastrectomy at our institution and 246 patients with elevated postoperative D-dimer levels who received Doppler ultrasonography of lower/upper extremity veins were enrolled. Clinicopathological factors data were collected, and the differences in clinicopathological factors between postoperative VTE (+) and VTE (-) groups were analyzed. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors of postgastrectomy VTE.

RESULTS

Of 246 patients with elevated postgastrectomy D-dimer concentrations, 74 patients showed thrombosis in lower/upper extremity veins. Among preoperative factors, age, WBC level, D-dimer concentration, and blood glucose level were significantly higher in the postoperative VTE (+) group. Among the postoperative factors, hemoglobin level was significantly lower in the postoperative VTE (+) group. Among the pathological factors, tumor stage, depth of invasion and TNM classification indicated higher malignancy in the postoperative VTE (+) group. Univariate logistic regression analysis indicated age, preoperative blood glucose level, postoperative hemoglobin level, tumor stage, depth of invasion, and TNM classification as the independent risk factors for postgastrectomy VTE, whereas multivariate logistic regression analysis revealed age and tumor stage as independent risk factors for postgastrectomy VTE.

CONCLUSION

Our study revealed that age, preoperative blood glucose level, postoperative anemia, and tumor malignancy were independent risk factors for GC patients exhibiting postgastrectomy VTE. Therefore, the perioperative monitoring, assessment and management of risk factors are important in achieving better outcomes after gastrectomy.

The Efficacy of the Systemic Immune-Inflammation Index and Prognosis Nutritional Index for the Diagnosis of Venous Thromboembolism in Gastrointestinal Cancers

Purpose

This study aimed to analyze the association between venous thromboembolism (VTE) and inflammatory markers like systemic immune-inflammation index (SII) and prognosis nutritional index (PNI), and to evaluate their efficacy for the diagnosis of VTE in patients with gastrointestinal malignancies.

Patients and Methods

A total of 1326 patients with the initial diagnosis of gastrointestinal cancer in the First Affiliated Hospital of Anhui Medical University (AHMU) were enrolled in the training cohort. Univariate and multivariate analysis was used to pinpoint independent predictors of VTE, which were eventually visualized as the nomogram models. The Akaike Information Criterion (AIC) was used to screen the best model. The receiver operating characteristic curve (ROC) and the clinical decision curve analysis (DCA) were utilized to evaluate the models’ predictive performance in the training queue and another external sample of 250 patients at the Second Affiliated Hospital of AHMU.

Results

A total of 476 patients were complicated with VTE in the training cohort. Multifactorial analysis of clinical characteristics and inflammatory markers showed that PNI, SII, age, tumor location, and therapy were independent risk factors of VTE, visualized as model A. Another model B was constructed by adding coagulation markers to the previous analysis. Model B was the best prediction model with the minimum AIC value, followed by model A with an AUC of 0.806 (95% CI 0.782~0.830) which was similar to model B’s 0.832 (95% CI 0.810~0.855) but significantly higher than the currently widely used Khorana score’s 0.592 (95% CI 0.562~0.621) and the CATS score’s 0.682 (95% CI 0.653~0.712). The external verification yielded similar findings, with the AUC being 0.792 (95% CI 0.734~0.851), 0.834 (95% CI 0.778~0.890), 0.655 (95% CI 0.582~0.729), and 0.774 (95% CI 0.699~0.849) respectively. The DCA curves demonstrated that new models had excellent usefulness in screening patients with a high VTE risk.

Conclusion

The SII and PNI were simple and viable inflammatory markers associated with VTE, and the nomogram based on them and clinical features had a meaningful clinical utility for VTE in patients with gastrointestinal malignancies.

Neutrophil extracellular traps participate in the development of cancer-associated thrombosis in patients with gastric cancer

BACKGROUND

The development of venous thromboembolism (VTE) is associated with high mortality among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlate with the prothrombotic state in some diseases, but are rarely reported in GC patients.

AIM

To investigate the effect of NETs on the development of cancer-associated thrombosis in GC patients.

METHODS

The levels of NETs in blood and tissue samples of patients were analyzed by ELISA, flow cytometry, and immunofluorescence staining. NET generation and hypercoagulation of platelets and endothelial cells (ECs) in vitro were observed by immunofluorescence staining. NET procoagulant activity (PCA) was determined by fibrin formation and thrombin–antithrombin complex (TAT) assays. Thrombosis in vivo was measured in a murine model induced by flow stenosis in the inferior vena cava (IVC).

RESULTS

NETs were likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies showed that GC cells and their conditioned medium, but not gastric mucosal epithelial cells, stimulated NET release from neutrophils. In addition, NETs induced a hypercoagulable state of platelets by upregulating the expression of phosphatidylserine and P-selectin on the cells. Furthermore, NETs stimulated the adhesion of normal platelets on glass surfaces. Similarly, NETs triggered the conversion of ECs to hypercoagulable phenotypes by downregulating the expression of their intercellular tight junctions but upregulating that of tissue factor. Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin formation and the TAT complex. In the models of IVC stenosis, tumor-bearing mice showed a stronger ability to form thrombi, and NETs abundantly accumulated in the thrombi of tumor-bearing mice compared with control mice. Notably, the combination of deoxyribonuclease I, activated protein C, and sivelestat markedly abolished the PCA of NETs.

CONCLUSION

GC-induced NETs strongly increased the risk of VTE development both in vitro and in vivo. NETs are potential therapeutic targets in the prevention and treatment of VTE in GC patients.

A retrospective study of the role of preoperative ultrasonography in the detection of deep vein thrombosis in 1750 patients with gastric and colorectal cancers

BACKGROUND

There has been a lack of research in the past on the prevalence and risk factors associated with deep vein thrombosis (DVT) in patients with resectable gastric and colorectal cancers. The purpose of this study was to review the anatomical distribution, prevalence and risk factors associated with lower limb DVT in 1750 patients with preoperative gastric and colorectal cancers and to evaluate the role of preoperative ultrasonography in the detection of DVT in preventing postoperative pulmonary thromboembolism (PTE) in patients with gastric and colorectal cancers.

METHODS

A total of 1750 patients with gastric and colorectal cancers who underwent preoperative venous ultrasonography of the lower limbs were retrospectively reviewed. The risk factors associated with preoperative DVT were identified using univariate and multivariate logistic regression analysis.

RESULTS

Seventy-three of the 1750 patients with gastric and colorectal cancers had DVT detected by preoperative venous ultrasonography of the lower limb and the incidence of lower limb DVT was 4.17 % in 1750 patients with gastric and colorectal cancers. Univariate analysis showed a higher risk of DVT in patients who met the following criteria: aged ≥80 years, female sex, the performance status ≥1, stage IV, ASA class ≥ III/IV, and hypertension. Multivariate logistic regression analysis showed that female sex, stage IV and ASA class ≥ III/IV were significantly associated with DVT before gastric and colorectal cancer surgery.

CONCLUSIONS

Our study showed that female sex, stage IV and ASA class ≥ III/IV were significantly associated with DVT before gastric and colorectal cancer surgery. Routine venous ultrasonography for the lower limb can identify the risk of PTE, which is of great significance in the prevention and occurrence of PTE.

Impact of routine preoperative sonographic screening with early intervention for deep venous thrombosis in lower extremities on preventing postoperative venous thromboembolism in patients with gastric cancer scheduled for minimally invasive surgery

PURPOSE

This study aimed to investigate the clinical efficacy of lower-extremity ultrasonography screening with early intervention for deep venous thrombosis (DVT) on the incidence of venous thromboembolism (VTE) after minimally invasive surgery (MIS) for gastric cancer (GC).

METHODS

Between January 2012 and December 2019, 1070 patients were diagnosed with both clinical and pathological stage I-III GC and underwent MIS at our institution. Routine ultrasonographic screening for DVT in lower extremities is performed before MIS. Patients diagnosed with DVT were preoperatively administered anticoagulant therapy. Enoxaparin was routinely administrated after surgery irrespective of the presence of DVT. The incidence of postoperative symptomatic VTE was examined retrospectively.

RESULTS

A total of 74 (6.9%) patients were preoperatively diagnosed with DVT. Multivariate analyses revealed that age > 70 years (p = 0.015), female sex (p < 0.001), and positive serum D-dimer test (p < 0.001) were significant and independent risk factors for preoperative DVT. The incidence of symptomatic postoperative VTE was 1 (0.09%); symptomatic VTE developed in one patient among patients without DVT, whereas no patient with DVT developed VTE.

CONCLUSIONS

Preoperative DVT screening using lower-extremity ultrasonography followed by preoperative anticoagulant therapy should be considered as a useful strategy to safely perform MIS for GC without increasing the incidence of VTE.

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.

Preoperative prevalence and risk factors of deep-vein thrombosis in Japanese surgical patients with ulcerative colitis: a retrospective investigational study

PURPOSE

The purpose of this study was to clarify the perioperative deep-vein thrombosis (DVT) prevalence and its risk factors in surgical ulcerative colitis (UC) patients by comparing the results with those in surgical colorectal cancer (CRC) patients at a high risk of perioperative venous thrombosis.

METHODS

This retrospective, observational study included patients who underwent surgery for UC or CRC between January 2013 and October 2019. Consecutive surgical patients with a positive D-dimer assay result (≥ 1.0 µg/ml) underwent lower-extremity venous ultrasonography. The prevalence and risk factors for preoperative DVT were examined in UC patients.

RESULTS

A total of 101 UC patients and 593 CRC patients were deemed eligible. Among the D-dimer positive cases, there were no significant differences between the two groups in the preoperative DVT prevalence (UC: 21.8% vs. CRC: 28.8%, p = 0.151), distal type (18.8% vs. 27.2%, p = 0.086), or proximal type (5.9% vs. 4.2%, p = 0.434). Furthermore, multivariate analyses showed that an older age, overweight status, poor ASA status, and a high preoperative dose of steroid were independent risk factors for preoperative DVT in UC surgical patients.

CONCLUSIONS

The risk of perioperative thrombosis in UC patients was considered similar to that in CRC, so active thromboprophylaxis should be administered to UC patients while paying attention to bleeding.

TRIAL REGISTRATION

This study was registered with the Japanese Clinical Trials Registry as UMIN000042004 ( http://www.umin.ac.jp/ctr/index.htm ).

Venous thromboembolism after esophagectomy for cancer: a systematic review of the literature to evaluate incidence, risk factors, and prophylaxis

PURPOSE

Although esophagectomy remains the preferred treatment for esophageal cancer, it is still associated with a number of complications, including post-operative venous thromboembolism (VTE). The aim of this study was to summarize the reported incidence of VTE after esophagectomy, its risk factors, and prevention strategies.

METHODS

We conducted a systematic search of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Fourteen studies met our inclusion criteria and were selected in the present review. Overall, we identified 9768 patients who underwent esophagectomy, with a post-operative VTE rate of 4% (440 patients). The reported risk factors for VTE included advanced age, American Society of Anesthesiologists (ASA) class III or IV, a history of cardiovascular or pulmonary disease, and the implementation of preoperative chemo-radiotherapy. Postoperative acute respiratory distress syndrome was also associated with VTE. No universally applied prevention strategies for VTE after esophagectomy were identified in the literature.

CONCLUSIONS

Despite advances in perioperative care, VTE after esophagectomy still represents a source of morbidity for about 4% of patients. Low molecular weight heparin is suggested as the routine standard prophylactic regimen after esophageal cancer surgery.

Risk of venous thromboembolism in patients undergoing gastric cancer surgery: protocol for a systematic review and meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a serious life-threatening complication in patients with gastric cancer. Abnormal coagulation function and tumour-related treatment may contribute to the occurrence of VTE. Many guidelines considered that surgical treatment would put patients with cancer at high risk of VTE, so positive prevention is needed. However, there are no studies that have systematically reviewed the postoperative risk and distribution of VTE in patients with gastric cancer. We thus conduct this systematic review to determine the risk of VTE in patients with gastric cancer undergoing surgery and provide some evidence for clinical decision-making.

METHODS AND ANALYSIS

Studies reporting the incidence of VTE after gastric cancer surgery will be included. Primary studies of randomised controlled trials, cohort studies, population-based surveys and cross-sectional studies are eligible for this review and only studies published in Chinese and English will be included. We will search the Medline, Embase, Web of Science, CBM, CNKI and Wanfang data from their inception to November 2019. Two reviewers will independently select studies and extract data. The quality of each included study will be assessed with tools corresponding to their study design. Meta-analysis will be used to pool the incidence data from included studies. Heterogeneity of the estimates across studies will be assessed, if necessary, a subgroup analysis will be performed to explore the source of heterogeneity. The Grades of Recommendation, Assessment, Development and Evaluation method is applied to assess the level of evidence obtained from this systematic review.

ETHICS AND DISSEMINATION

This proposed systematic review and meta-analysis is based on published data, and thus ethical approval is not required. The results of this review will be sought for publication.

PROSPERO REGISTRATION NUMBER

CRD42019144562.

Clinical analysis of preoperative deep vein thrombosis risk factors in patients with colorectal cancer: Retrospective observational study

AIM

Deep vein thrombosis (DVT) is a major complication of cancer. The postoperative prevalence of DVT in colorectal cancer (CRC) surgery is high, but the preoperative prevalence and the risk factors have not been clarified in detail. The objective of this retrospective study was to investigate the preoperative prevalence and risk factors of DVT in patients admitted to hospital for CRC surgery.

METHODS

From January 2013 to March 2017, 1006 patients admitted for CRC surgery were deemed eligible for this retrospective study. Diagnosis of preoperative DVT was confirmed by compression ultrasonography. Prevalence of silent DVT in lower limbs in patients before CRC surgery was assessed, and the risk factors for preoperative DVT were investigated regarding the correlation of DVT with the patient's background.

RESULTS

Preoperative DVT and asymptomatic pulmonary thromboembolism were diagnosed in 136 (13.5%) and in 10 (1.0%) of 1006 patients overall, respectively. Multivariate analysis showed that increased age (≥75 years), female gender, and an elevated d-dimer level (>1.0 μg/mL) were independent risk factors for preoperative DVT in this study. Notably, the prevalence of preoperative DVT exceeded 50% in patients with all three predictors.

CONCLUSIONS

A high prevalence (13.5%) of preoperative DVT was found in patients admitted to the hospital for CRC surgery. The present results suggest that instrumental screening should be encouraged, at least in subgroups at a higher risk of preoperative DVT.

Venous thromboembolism in cancer patients receiving neoadjuvant chemotherapy: a systematic review and meta-analysis

Essentials Cancer patients are at risk for venous thromboembolism (VTE). The risk of VTE in less advanced stage cancer on neoadjuvant chemotherapy is unclear. In over 7800 patients, we found a 7% pooled incidence of VTE during neoadjuvant therapy. Highest VTE rates were observed in patients with bladder and esophageal cancer.

SUMMARY

Background Venous thromboembolism (VTE) is a frequent complication in cancer patients receiving adjuvant treatment. The risk of VTE during neoadjuvant chemo-radiotherapy remains unclear. Objectives This systematic review evaluated the incidence of VTE in patients with cancer receiving neoadjuvant treatment. Methods MEDLINE and EMBASE databases were searched from inception to October 2017. Search results were supplemented with screening of conference proceedings of the American Society of Clinical Oncology (2009-2016) and the International Society of Thrombosis and Haemostasis (2003-2016). Two review authors independently screened titles and abstracts, and extracted data onto standardized forms. Results Twenty-eight cohort studies (7827 cancer patients, range 11 to 1398) were included. Twenty-five had a retrospective design. Eighteen cohorts included patients with gastrointestinal cancer, representing over two-thirds of the whole study population (n = 6002, 78%). In total, 508 of 7768 patients were diagnosed with at least one VTE during neoadjuvant treatment, for a pooled VTE incidence of 7% (95% CI, 5% to 10%) in the absence of substantial between-study heterogeneity. Heterogeneity was not explained by site of cancer or study design characteristics. VTE presented as pulmonary embolism in 22% to 96% of cases (16 cohorts), and it was symptomatic in 22% to 100% of patients (11 cohorts). The highest VTE rates were observed in patients with bladder (10.6%) or esophageal (8.4%) cancer. Conclusions This review found a relatively high incidence of VTE in cancer patients receiving neoadjuvant therapy in the presence of some between-study variation, which deserves further evaluation in prospective studies.

Risk and incidence of perioperative deep vein thrombosis in patients undergoing gastric cancer surgery

BACKGROUND AND PURPOSE

Venous thromboembolism (VTE) is a potentially fatal perioperative complication. Understanding the risk factors for deep vein thrombosis (DVT) and initiating appropriate prophylaxis is pivotal for reducing the risk of VTE. The purpose of this study was to clarify the perioperative risk factors for DVT in patients undergoing surgery for gastric cancer.

METHODS

We reviewed the findings of lower limb ultrasonography performed in 160 patients who underwent gastrectomy for gastric cancer.

RESULTS

The preoperative and postoperative incidence of DVT was 4.4% (7/160) and 7.2% (11/153), respectively. All postoperative DVTs were of the distal type, whereas preoperative DVTs were of the proximal (n = 3) and distal type (n = 4). None of the patients suffered symptomatic VTE. Multivariate analysis indicated that depth of invasion and D-dimer concentration were independent risk factors for preoperative DVT and that gender and performance status were risk factors for postoperative DVT. Receiver operating characteristic analysis revealed that the optimal cut-off D-dimer concentration was 1.4 μg/mL.

CONCLUSIONS

The incidence of perioperative DVT was low for patients undergoing gastric cancer surgery. Therefore, the risk-stratified application of perioperative pharmacologic thromboprophylaxis is thought to be more appropriate than routine pharmacologic thromboprophylaxis for Japanese patients undergoing surgery for gastric cancer.