This study will determine whether a newly developed blood test, known as the whole blood thrombin generation assay (WBTGA), will detect hypercoagulability-that is, increased capacity to generate thrombin, the enzyme that promotes blood clotting. Major surgery and metastatic cancer, or cancer that has spread, are risk factors for blood clots developing in the leg veins and lungs. That process is known as venous thromboembolism (VTE). Even with current measures taken to offer anticoagulation protection to patients following their surgery, the incidence of VTE is about 5%. Few laboratory tests are available to evaluate the risk of VTE in a patient. In this study, investigators will explore whether the new WBTGA is different in patients with cancer compared with healthy people, and to see whether the test changes after a patient has major surgery. The premise of the WBTGA is that total thrombin production is directly related to the ability of the blood to coagulate.

Patients age 18 or older who are enrolled in one of four Surgery Branch protocols for the treatment of metastatic cancer may be eligible for this study. Those who are taking anticoagulants, have taken aspirin within the last 7 days, are taking estrogen contraceptives or hormone replacement, or have had infections or other acute illness within the last 14 days are not eligible. Healthy control participants will be recruited from among NIH employees, primarily staff in the Department of Laboratory Medicine. It will be necessary for participants to undergo a blood test for the presence of the antibodies for HIV, the virus that causes AIDS. About 2 teaspoons of blood will be drawn.

For the study, surgical patients will be asked to give blood samples twice-once within 7 days before surgery and once the day after surgery. About a tablespoon of blood will be collected each time. Participants who make up the control group will give about a tablespoon of blood only once. These blood samples will be used for the new test as well as for other tests that are not new but that may be helpful in understanding changes in blood clotting that occur following surgery. To the extent possible, the blood samples will be collected at the same time that participants are giving blood for other tests, to help in avoiding an extra needle stick.

No form of treatment is involved in this study. There is no direct benefit from participating, but those in the control group will receive $20.

The likelihood of venous thromboembolism (VTE) in individual patients can be only roughly estimated on the basis of clinical factors. Theoretically, global laboratory tests that detect hypercoagulability would be helpful in predicting thrombosis in the same way that routine tests for hypocoagulability (eg., PT, aPTT) are in predicting bleeding. However, clinically useful tests for hypercoagulability are currently not available. The goal of this study is to determine whether a newly developed blood test, the 'whole blood thrombin generation assay,' will detect hypercoagulability (defined as increased capacity to generate thrombin) in patients with metastatic carcinoma before and/or after major intra-abdominal surgery. This patient population was selected because both metastatic carcinoma and major surgery are associated with a significant risk of VTE. Thirty patients with metastatic carcinoma and a healthy control group will be studied. A battery of tests will also be run to measure specific plasma components known to be important in coagulation pathways. The pre-operative results of the patients will be compared with their postoperative data and with the results from the healthy control group.

• INCLUSION CRITERIA

Patients:

-must be enrolled in one of four Surgery Branch protocols (99-C-0123L, 00-C-0069, 03-C-0085, 03-C-02121A), for the treatment of metastatic carcinoma.

Control subjects:

-must be greater than or equal to 18 years old. Control subjects will be selected on the basis of their sex and age to match the patients as they are accrued.

EXCLUSION CRITERIA

Patients and Control Subjects:

• must not be taking anticoagulants: Pre-operative prophylactic anticoagulation must not be anticipated. (The decision regarding the need for pre-operative anticoagulation will be made by the surgical team on an individual basis.)
• must not have taken aspirin for at least 7 days, and for at least three days no other drugs known to inhibit platelet function.
• must not be taking estrogen contraceptives or hormone replacement.
• must not have had symptomatic infections or other acute illness for at least 14 days.

Control Subjects:

• must not be known to be anemic or thrombocytopenic.
• must not have a history of VTE (deep vein thrombosis, pulmonary emboli), coronary artery disease or stroke, chronic inflammatory disease, diabetes mellitus, smoking tobacco within 6 months, infection within previous 14 days.