When blood clots develop in cancer patients, 78% of the time they occur when a person is out of the hospital, while on chemotherapy. This remarkable fact comes from a study of nearly 18,000 cancer patients by researchers at the University of Rochester Medical Center (URMC).
Until now, previous data collected on the frequency of blood clots were mostly from hospitalized patients. Outpatients had yet to be thoroughly studied. However, as oncology care shifts toward outpatient cancer treatment, the efforts toward preventing blood clots should focus on helping patients to avoid complications so they can continue to live fully, by working, raising children, and exercising, during treatment, said Alok Khorana, MD, associate professor in the James P. Wilmot Cancer Center at URMC, and an international authority on venous thromboembolism (VTE).
“One in five patients develops blood clots after a cancer diagnosis and we believe that number is rising,” Khorana said. “The Surgeon General recently issued a Call to Action to reduce VTE. At this point public health efforts have focused on inpatient prophylaxis. These new data suggest that to reduce the burden of VTE in cancer patients, prevention efforts will have to shift to the outpatient arena as well.”
The retrospective, observational study conducted by Khorana and his research team between 2005 and 2009 utilized healthcare claims databases for both inpatients and outpatients. According to the study, 5.6% of the 17,784 cancer patients identified developed blood clots. Of those who experienced this complication, 21% had recently been hospitalized; however, 78.3% were being treated on an outpatient basis.
Cancer patients are more vulnerable to blood clots for many reasons:
- The tumor can secrete proteins related to blood clots
- Treatments (surgery, chemotherapy, hormonal therapy) raise the risk of clots
- Limited mobility due to active disease or hospitalization
- Genetic predisposition
- Other health issues (infections, obesity, anemia, lung disorders)
Furthermore, once a patient develops a blood clot, that individual is much more likely to experience clots in the future.
“Ongoing public health issues that we must address are how to educate patients on the importance of blood clot prevention, and improving compliance to preventive treatment,” Khorana said.