Aim: To investigate the efficacy and safety of anticoagulant prophylaxis to prevent postoperative venous thromboembolism (VTE) during laparoscopic colorectal cancer (CRC) surgery, which is unknown in Japanese patients.Methods: We conducted this randomized controlled trial at nine institutions in Japan from 2011 to 2015. It included 302 eligible patients aged 20 years or older who underwent elective laparoscopic surgery for CRC. Patients were randomly assigned to an intermittent pneumatic compression (IPC) therapy group or to an IPC + anticoagulation therapy group. Anticoagulation therapy comprised fondaparinux or enoxaparin for postoperative VTE prophylaxis. Postoperative VTE was diagnosed based on enhanced multi‐detector helical computed tomography. The primary endpoint was VTE incidence, including asymptomatic cases, the secondary endpoint was incidence of major bleeding, and we conducted an intention‐to‐treat analysis. This study is registered in UMINCTR (UMIN000008435).Results: Postoperative VTE incidence was 5.10% with IPC therapy (n = 157) and 2.76% with IPC + anticoagulant therapy (n = 145; P = .293). We identified no symptomatic VTE cases. The major bleeding rates were 1.27% with IPC alone and 1.38% with the combination (P = .936). The overall bleeding rates were 7.69% for enoxaparin and 13.6% for fondaparinux (P = .500), and there were no bleeding‐related deaths.Conclusion: Anticoagulant prophylaxis did not reduce the incidence of VTE and the incidence of major bleeding was comparable between the two groups. Usefulness of perioperative anticoagulation was not demonstrated in this study. Pharmacological prophylaxis must be restricted in Japanese patients with higher risk of VTE.

Aim: To investigate the frequency and risk factors of perioperative, symptomatic venous thromboembolism (VTE) after gastroenterological surgery.Methods: We assessed the frequency of and risk factors for VTE after eight gastroenterological procedures (total 516 217 cases including, gastrectomy, total gastrectomy, hepatectomy, esophagectomy, right hemicolectomy, low anterior resection, pancreaticoduodenectomy, and acute pan‐peritonitis surgery) based on data from the National Clinical Database. Data collected between 2011 and 2013 (382 124 cases) were used as a test set, and data from 2014 (134 093 cases) were used as a validation set.Results: The frequency of deep vein thrombosis (DVT) was 0.3% (382 124 cases), and the incidence of pulmonary embolism (PE) was 0.2% (382 124 cases) ranging from 0.1% to 0.7% for DVT and from 0.1% and 0.3% for PE among eight surgeries, respectively. Analyses using pre‐and intra‐operative factors identified the top three risk factors for VTE as esophagectomy, pancreaticoduodenectomy, and hepatectomy. Using pre‐, intra‐, and postoperative factors, the second through fourth risk factors were sepsis, prolonged ventilation >48 hours and readmission within 30 days. The highest risks factor for PE using pre‐, intra‐, and postoperative factors were any cardiac events. Unplanned intubation was the fourth risk factor.Conclusion: The risk for DVT and PE differed for each surgical procedure. VTE and PE risk factors changed after considering postoperative factors. It may be necessary to reconsider the prophylaxis depending on whether the complication occurs after surgery, particularly breathing and cardiac complications.

Although number of elderly patients with metastatic colorectal cancer (mCRC) is rapidly increasing, this population is often underrepresented in clinical trials. Recently, a phase II trial demonstrated that capecitabine and oxaliplatin (XELOX) combined with bevacizumab XELOX plus bevacizumab was effective and well tolerated by elderly patients with mCRC who reside in Western countries. The aim of this study was to evaluate the safety and efficacy of XELOX plus bevacizumab for Japanese patients aged ≥75 years with mCRC. This prospective, open-label phase II trial recruited patients aged ≥75 years with previously untreated mCRC between March 2010 and January 2012. Treatment consisted of 7.5 mg/kg of intravenous bevacizumab and 130 mg/m2 of oxaliplatin on day 1 of each cycle combined with 2000 mg/m2 of oral capecitabine per day on days 1–14 of each cycle. Treatment was repeated every 3 weeks until disease progression or termination of the study. The primary endpoint was progression-free survival; the secondary endpoints were toxicity, overall response rate, time-to-treatment failure, and overall survival. Thirty-six patients (male 58 %; median age 78 years; colon cancer 67 %) met all eligibility criteria and received at least one course of the planned treatment. The median time-to-treatment failure was 7.0 months. Twelve patients (33.3 %) experienced adverse effects (AEs) ≥ grade 3 and frequent AEs ≥ grade 3, including neutropenia (22.2 %) and neuropathy (13.9 %). Hypertension was the most frequent AE ≥ grade 3 associated with bevacizumab (11.1 %). Low baseline creatinine clearance associated significantly with the incidence of AEs ≥ grade 3. Response and disease control rates were 55.6 and 91.7 %, respectively. Median progression-free and overall survival times were 11.7 months (95 % confidence interval, 8.0–13.4 months) and 22.9 months, respectively. XELOX combined with bevacizumab was well tolerated by selected Japanese patients aged ≥75 years with mCRC patients, and controlled clinical trials are now required to determine the survival benefit.