By: Ed Susman

NEW ORLEANS, LA – Researchers recently suggested at the American Society of Hematology 51st Annual Meeting and Exposition that patients with pancreatic cancer might benefit from low-molecular-weight heparin therapy to prevent venous thromboembolism, but in general the benefit in preventing thromboembolism in other cancers is offset by increased bleeding risks.

Researchers performed a meta-analysis of 8 randomised trials that enrolled ambulatory cancer patients and reported those results in an oral presentation at the annual meeting.

Overall, the use of low-molecular-weight heparin significantly reduced the risk of thromboembolic events by 47% (P < .001), according to Nicole Kuderer, MD, Duke University Medical Center, Raleigh, North Carolina.

However, almost all the benefit was driven by the success of treatment in 2 pancreatic cancer trials, she said. The meta-analysis included only studies that compared patients randomised to receive low-molecular-weight heparin with those who did not receive it and studies that reported the rates of thrombosis or blood clots.

Most of the studies — which enrolled more than 3,000 patients — lumped solid tumour pathology together, making it difficult to pinpoint particular diseases where prophylaxis would be beneficial, said Dr. Kuderer.

However, 2 of the studies were specifically aimed at patients diagnosed with pancreatic cancer. In both studies, patients received gemcitabine. In the CONKO-04 (Charité Onkologie) trial, pancreatic cancer patients were treated with enoxaparin. In the FRAGEM (Chemotherapy With or Without Dalteparin) trial, 123 patients were randomised to receive dalteparin.

When the 6 studies that didn’t specifically look at pancreatic cancer were considered, Dr. Kuderer found a significant reduction of 36% in venous thromboembolic events. In the pancreatic cancer trials the decrease was 64%.

In pancreatic cancer there was an absolute decreased risk of a thromboembolic events, which was offset by a 0.8% increase in the risk of serious bleeding.

In the studies that did not deal specifically with pancreatic cancers, the absolute risk reduction of 1.4% was almost totally negated by the 0.9% risk of bleeding.

“Weighing the risks and benefits, routine venous thromboembolism prophylaxis in the general cancer population cannot be recommended at this time,” Dr. Kuderer said. “In contrast, the risk benefit profile of low-molecular-weight heparin appears very promising in advanced pancreatic cancer patients on gemcitabine-based chemotherapy.”

“Since the bleeding risk in this group was also just under 1%, it strongly suggests that routine use of blood thinners in these patients makes sense,” she added. “The risk/benefit equation appears similar if not better than in hospitalised patients.”

Dr. Kuderer noted that the data on the pancreatic cancer patients come from early study reports that still need to be peer-reviewed and published.

- MFP Wire Services
- 12-11-2009