Researchers study prevention of blood clots in cancer patients

Oct 08, 2008

As more individuals with cancer are being treated as outpatients, the University of Rochester Medical Center is working on an emerging problem: how to prevent the life-threatening blood clots that can accompany some newer cancer drugs.

A team of researchers, awarded $3 million this month by the National Heart, Lung and Blood Institute, is seeking to change the current standard of care by conducting a landmark clinical trial. They will test whether the drug dalteparin, a low-molecule-weight heparin available in a once-daily injection, can prevent pulmonary embolism or other forms of venous thromboembolism (VTE) in patients receiving chemotherapy on an outpatient basis.

The team includes Principal Investigator Charles W. Francis, M.D., professor of Medicine in Hematology/Oncology at the University's James P. Wilmot Cancer Center, and URMC co-investigators Alok A. Khorana, M.D., associate professor of Medicine in Hematology/Oncology, and Mark B. Taubman, M.D., chair of the Department of Medicine and a member of the Aab Cardiovascular Research Institute. Duke University is a research partner as well.

Until recently, physicians had no way to identify which cancer patients might be at higher risk for the clots. But the Rochester group designed a risk model that was published in the journal, Blood. Then, based on input from the Rochester experts, the American Society of Clinical Oncology in 2007 issued its first set of guidelines for clinicians on clot prevention for cancer patients. The next step is to demonstrate that clots can be prevented among those identified as higher risk.

"Venous thromboembolism is one of the leading complications in cancer patients and is the second leading cause of death," Francis said. "We expect that the results of this trial will show the way in preventing these problems and improving care for patients with cancer."

When blood clots develop in the deep veins of the leg or thigh, they can block blood flow and cause pain. In more serious cases, the clot breaks loose and travels to the lungs where it blocks arteries and can be fatal. Being hospitalized or confined to bed rest are risk factors, but clots can also develop in more active people.

Hospitalized patients routinely are given drugs such as dalteparin to prevent or treat the clots as soon as they develop. In the outpatient setting, however, the protocol for cancer treatment does not include using a drug such as Dalteparin for prevention of clots.

"The difficulty for outpatients is that not everyone who has a blood clot is symptomatic," Khorana said. "And in some cases when they do have symptoms of a clot in the lungs, the patient will complain of chest pains, shortness of breath, fatigue or a cough, which can be confused with cancer symptoms."

The Acting United States Attorney General Steven K. Galson, M.D., M.P.H., issued a "call to action" on Sept. 15, 2008, to reduce the number of cases of deep vein thrombosis and pulmonary embolism by urging people to learn more about the condition. The government estimates that up to 600,000 Americans each year suffer from dangerous clots, and that number is expected to rise as the baby-boomer population ages.

Scientists also believe the incidence may be growing with the use of a newer class of cancer therapies called anti-angiogenesis drugs, such as Avastin. Although these newer drugs have less toxicity than chemotherapy, some are associated with higher rates of VTE.

In addition, the properties of some tumors may promote clots. Cancer-associated VTE leads to interruption of therapy, hospitalizations and increased risk of death.

To better understand the biological components of VTE risk in cancers, the Rochester group, led by Taubman, will also study whether elevated levels of tissue factor (TF) in plasma is a predictor of blood clots in cancer patients. Tissue factor is a protein in platelets that plays a vital role in how coagulation occurs and the promotion of blood clots. They will test the TF hypothesis using blood samples and biopsy specimens from patients who enroll in the Dalteparin clinical trial, and from a control group of patients identified as having a low risk of clots.

For years Taubman has been investigating the role of tissue factor in heart disease. But more recently he discovered data that shows certain cancers are also associated with elevated levels of TF, particularly pancreatic cancer. TF levels also tend to be higher in prostate cancer patients who survive for years.

The reasons for increased TF are not completely understood, but scientists do know that as cancer cells grow and die, they dump TF into the bloodstream. Chemotherapy also contributes to more TF entering the bloodstream as the cancer cells die off.

"This grant puts us in the forefront nationally of this growing field of inquiry," Taubman said. "I am confident that we will be the ones to answer the questions about cancer-associated tissue factor and whether anti-coagulant therapy has an effect of the risk of blood clots in cancer patients."

Source: University of Rochester

Explore further: Recorded Ebola deaths top 7,000

add to favorites email to friend print save as pdf

Related Stories

Shape of things to come in platelet mimicry

Nov 05, 2014

Artificial platelet mimics developed by a research team from Case Western Reserve University and University of California, Santa Barbara, are able to halt bleeding in mouse models 65 percent faster than nature ...

Molecular beacons shine light on how cells 'crawl'

Oct 24, 2014

Adherent cells, the kind that form the architecture of all multi-cellular organisms, are mechanically engineered with precise forces that allow them to move around and stick to things. Proteins called integrin ...

Improvement in prediction of blood clots in cancer patients

Sep 09, 2010

For cancer patients, who have an increased risk of developing venous thromboembolism (VTE) due to a hyperactive blood coagulation system, there is now an enhanced risk model to predict their chance of developing blood clots, ...

Atomic structure of key muscle component revealed

Jul 24, 2014

Actin is the most abundant protein in the body, and when you look more closely at its fundamental role in life, it's easy to see why. It is the basis of most movement in the body, and all cells and components ...

Recommended for you

Recorded Ebola deaths top 7,000

18 hours ago

The worst Ebola outbreak on record has now killed more than 7,000 people, with many of the latest deaths reported in Sierra Leone, the World Health Organization said as United Nations Secretary-General Ban ...

Liberia holds Senate vote amid Ebola fears (Update)

22 hours ago

Health workers manned polling stations across Liberia on Saturday as voters cast their ballots in a twice-delayed Senate election that has been criticized for its potential to spread the deadly Ebola disease.

Evidence-based recs issued for systemic care in psoriasis

Dec 19, 2014

(HealthDay)—For appropriately selected patients with psoriasis, combining biologics with other systemic treatments, including phototherapy, oral medications, or other biologic, may result in greater efficacy ...

Bacteria in caramel apples kills at least four in US

Dec 19, 2014

A listeria outbreak believed to originate from commercially packaged caramel apples has killed at least four people in the United States and sickened 28 people since November, officials said Friday.

Steroid-based treatment may answer needs of pediatric EoE patients

Dec 19, 2014

A new formulation of oral budesonide suspension, a steroid-based treatment, is safe and effective in treating pediatric patients with eosinophilic esophagitis (EoE), according to a new study in Clinical Gastroenterology and Hepatology, the official clinical practice journal ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.