Standard Therapy With or Without Dalteparin in Treating Patients With Advanced Breast, Lung, Colorectal, or Prostate Cancer

DISEASE CHARACTERISTICS: Histologically or cytologically proven breast, lung, colorectal, or prostate cancer that has failed prior chemotherapy or hormone therapy No active CNS metastases Hormone receptor status: Not specified PATIENT CHARACTERISTICS: Age: 18 and over Menopausal status: Not specified Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3500/mm3 Platelet count at least 150,000/mm3 Fibrinogen above lower limits of normal Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT no greater than 3 times ULN Prothrombin time no greater than 1.5 times ULN Active partial thromboplastin time no greater than 1.5 times ULN Renal: Creatinine no greater than 1.5 times ULN Other: No history of heparin associated thrombocytopenia At least 1 year since prior thromboembolic phenomenon such as deep venous thrombosis, pulmonary embolus, or clotted catheter No prior intolerance of unfractionated or low molecular weight heparin PRIOR CONCURRENT THERAPY: No concurrent anticoagulation therapy No concurrent enrollment on systemic or radiation therapy study (therapy off study allowed)