Nationwide retrospective cohort study of risk of venous thromboembolic events after surgery for cancer in Sweden

The risks and benefits of thromboprophylaxis therapy after cancer surgery are debated. Studies that determine thrombosis risk after cancer surgery with high accuracy are needed. A Sweden-wide retrospective cohort study included 432,218 patients who underwent major surgery for 8 cancer types with 4,009,343 matched general population comparators. There was a statistically significant increase in 1-year cumulative risk of venous thromboembolism in the cancer surgery patients.The initial increase in risk associated with the surgery was followed by a plateau that varied by cancer type. The authors conclude that these findings suggest that there is an increased risk of venous thromboembolism associated with cancer surgery, which varies both in magnitude and temporality by cancer type.