Venous thromboembolism in patients with cancer undergoing surgical exploration.

Malignancy and surgery are both independent risk factors for venous thromboembolism (VTE) events. The current NCCN guidelines recommend VTE prophylaxis for up to 28 days after major abdominal or pelvic surgery for malignancy. We set out to evaluate the rate and timing of VTEs among patients with gastric, pancreatic, colorectal, and gynecologic malignancies who underwent surgery. We performed a retrospective review of the NSQIP database (2005-2013) focusing on patients with gastric, colorectal, pancreatic, and gynecologic malignancies. Our primary endpoint was a diagnosis of VTE within 30 days of surgery. We analyzed 128,864 patients in this study. On multivariable analysis, patients with pre-operative sepsis (OR 2.36, CI 2.04-2.76, p < 0.001), disseminated cancer (OR 1.73, CI 1.55-1.92, p < 0.001), congestive heart failure (OR 1.69, CI 1.25-2.28, p = 0.001), gastric cancer (OR 1.3, CI 1.09-1.56, p = 0.004), and pancreatic cancer (OR 1.2, CI 1.03-1.30, p = 0.021) were more likely to have a VTE. Of patients who had a VTE event, 34% occurred after discharge from surgery (gastric: 25%, colorectal 34%, pancreatic 31%, gynecologic malignancy 42%). Our study demonstrates that patients who undergo an operation for malignancy with pre-operative sepsis, disseminated cancer, congestive heart failure, gastric cancer, or pancreatic cancer are more likely to develop a VTE within 30 days of their operation. Of those patients who developed a VTE, approximately one-third occurred after discharge during a 30 day post-operative period. This data supports that further studies are needed to determine the appropriate length of post-operative VTE chemoprophylaxis in patients with cancer.