Persistence of Risk for Venous Thromboembolism After Resection for Colorectal Cancer

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A team of researchers conducted a meta-analysis to determine the variation in incidence of venous thromboembolism following resection for colorectal cancer.

The incidence of venous thromboembolism (VTE) after resection for colorectal cancer is high and remains elevated more than 1 month after surgery, according to the results of a study published in Diseases of the Colon & Rectum.

Researchers conducted a meta-analysis to determine the variation in VTE incidence following resection for colorectal cancer. They searched Medline and Embase from database inception to August 2019, as well as 3 other registered medical databases.

Eligible studies included patients aged 18 years and older who underwent resection for colorectal cancer, and the main outcomes were 30-day and 90-day incidence rates of VTE per 1000 person-years following surgery.

A total of 18 large database/registry studies with 539,390 patients were included in the meta-analysis. The aggregated frequency of VTE events after colorectal cancer resection at 1 month was 1.92% and within 3 months was 2.43%. After conducting a pooled analysis, the researchers found that 30-day and 90-day incidence rates of VTE following resection for colorectal cancer were 195 (95% CI, 148-256; I2 99.1%) and 91 (95% CI, 56-146; I2 99.2%) per 1000 person-years, respectively.

When the analysis was separated according to United Nations geoscheme areas, the overall pooled incidence rates of VTE per 1000 person-years at 30 days and 90 days following resection were 284 (95% CI, 238-339) and 121 (95% CI, 82-179), respectively, in the Americas and 71 (95% CI, 60-84) and 57 (95% CI, 47-69), respectively, in Europe.

“In a pooled analysis of 18 study populations this review found that the incidence rate of VTE following surgery for CRC is high in the first 30 days after surgery,” stated the study authors. “The incidence rate decreases toward 90 days postoperatively. These high absolute rates are greater than previously reported VTE rates after benign general surgery.”

The investigators noted that their findings are limited by the high degree of heterogeneity observed within the meta-analysis, and more robust, worldwide population studies are needed.

The observed VTE rates suggest that extended prophylaxis may still be of benefit in the prevention of VTE, according to the researchers. The regional variation in VTE rates may result from differences in demographic and clinical practice factors, such as surveillance protocols.

“Therefore, when comparing rates of postoperative VTE against a regional standard it is necessary to acknowledge the rate observed may be influenced by these factors and what this means in terms of quality of care,” the study authors concluded.


Lewis-Lloyd CA, Pettitt EM, Adiamah A, et al. Risk of postoperative venous thromboembolism after surgery for colorectal malignancy: a systematic review and meta-analysisDis Colon Rectum. Published online January 18, 2021. doi:10.1097/DCR.0000000000001946