Chemotherapy With or Without Dalteparin in Treating Patients With Metastatic Pancreatic Cancer

RATIONALE: Drugs used in chemotherapy, such as gemcitabine and capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Anticoagulants, such as dalteparin, may help prevent blood clots from forming in patients being treated with chemotherapy. It is not yet known whether gemcitabine is more effective when given alone or together with dalteparin and/or capecitabine in treating patients with pancreatic cancer. PURPOSE: This randomized phase III trial is studying whether dalteparin prevents blood clots in patients with pancreatic cancer receiving treatment with different combinations of gemcitabine and capecitabine.