Thromboprophylaxis in cancer patients still presents many challenges, with the need to balance variably increased risk of venous thromboembolism (VTE) with the risk of bleeding.
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Cleveland Clinic researchers recently conducted a large a retrospective cohort study to improve understanding of the risks hospitalized cancer patients face in an effort to develop risk-adapted treatment approaches.
The study’s findings were presented at the 2016 American Society of Hematology Annual Meeting in San Diego.
Researchers examined data from a large cohort of patients admitted to a general oncology floor to identify risk factors predictive of bleeding during hospitalization. The incidence of major and clinically relevant bleeding was about 2 percent, compared to the incidence of inpatient VTE in a similar population of 4 percent. Morbid obesity, the type/site of malignancy, and anemia were among the factors predictive of bleeding.
According to one of the study’s authors, Alok Khorana, MD, Director of Cleveland Clinic’s Gastrointestinal Malignancies Program, this is one of the few studies to focus on bleeding risk in this way, to help identify patients especially at risk.
“Although thrombosis is recognized as an important complication of hospitalization, its converse, bleeding, is also very prevalent,” Dr. Khorana points out. “Patients often do not receive thromboprophylaxis because of concerns regarding bleeding risk. We felt it important to understand bleeding risk in order to better be able to address concerns regarding appropriate prevention of thrombosis.”
Study includes thousands
The study included 3,466 consecutive adults admitted to general oncology at Cleveland Clinic from 2013 to 2014. A total of 108 patients were excluded for bleeding on admission. The data collected included:
- Body mass index (BMI)
- Cancer type
- Length of stay (LOS)
- Use of anticoagulants
- Baseline laboratory values (+48 hours)
Bleeding was assessed using the ISTH definitions of major bleeding and clinically relevant non-major bleeding. Data was collected using an electronic query system of electronic health records. Reason for admission and all bleeding events were confirmed by manual chart review.
Predictors of bleeding found
Of the 3,358 patients included, 69 (2.1 percent) developed major and clinically relevant non-major bleeding during hospitalization. Median age was 62 years and 56 percent were male. Median length of stay was five days. The majority of bleeding events were either gastrointestinal (N=30, 43 percent) or intracranial (N= 13, 19 percent).
In univariate analysis, luminal gastrointestinal (GI) cancers (OR 4.2, CI 2.4-7.5, P<0.001), anemia as reason for admission (OR 9.1, CI 5.1-16.4, P<0.001), thrombocytopenia (OR 1.6, CI 1.0-2.6, P=0.046), leukocytosis (OR 2.1, CI 1.2-3.7, P=0.005), low hemoglobin (OR 3.2, CI 1.4-7.1 P=0.003) and BMI ≥ 40 kg/m2 (OR 2.6, CI 1.1-5.94, P=0.018) were significantly associated with bleeding.
In multivariable analysis, anemia as the reason for admission, primary cancer site, BMI>40, thrombocytopenia and low hemoglobin on admission remained predictive of bleeding.
The study concluded that incidence of major and clinically relevant bleeding in a large population of hospitalized cancer patients was about 2 percent, compared to incidence of inpatient VTE in a similar population of 4 percent. Risk factors at admission included type of cancer and morbid obesity.
“One implication of our study is that bleeding prevalence is not as high as that of thrombosis, adding to the challenge of thrombosis prevention, which is typically best achieved with anticoagulants that can increase bleeding risk,” says Dr. Khorana. “Risk-adaptive strategies and individualizing risk of both thrombosis and bleeding can help optimize the risk-benefit ratio.”
Improved prediction of bleeding risk
As a result of this study, Dr. Khorana believes these data will add to the body of knowledge that will be helpful in assessing a cancer patient’s risk for bleeding, which can help optimize appropriateness of prophylaxis.
“I think it will also add to the knowledge gaps related to bleeding risk and how it relates to thrombosis prevention,” he says.
But he adds that more research will be needed. “We need more prospective data on understanding risk factors and potentially a prediction tool to identify those at high risk for bleeding,” he says.