It has been reported that cancer increases the risk of VTE 4-6-fold. The incidence of VTE in cancer pts has been estimated at 1 in 200 per year and has been well documented in solid tumors. Far less is known about the incidence of VTE in pts with hematological malignancies although a recent publication (

Blom et al,
) suggested that pts with hematological malignancies such as lymphoma and multiple myeloma may be at a higher risk of developing VTE than pts with solid tumors. The incidence and risk of VTE has not been well studied in acute leukemias, a population in which prophylaxis is underutilized given the thrombocytopenia associated with intensive chemotherapy. To evaluate the incidence of VTE in pts with hematological malignancies further and to assess the need for VTE prophylaxis, we conducted a retrospective chart review of 299 pts with ALL, BL, or LL who were seen at M.D. Anderson Cancer Center Center from November 1999 to May 2005. Pts received a hyper-CVAD based regimen (fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone alternating with methotrexate and high-dose cytarabine). The median observation period was 188 weeks (range 1–328 wks) and included post-consolidation chemotherapy, allogeneic stem cell transplant, and/or salvage chemotherapy. Among 298 evaluable pts, 52 (17%) had confirmed VTE by imaging studies. In 7 pts, VTE was the presenting sign of the malignancy. The median age of pts who developed VTE was significantly higher than of those who did not develop VTE, 48.5 yrs (range 19–75) vs. 42 yrs (range 15–83), respectively (p=0.04). With each year increase in age, the risk of having VTE increased approximately by 1.7% (p=0.059). ALL pts with Philadelphia chromosome (Ph) had a higher incidence of VTE than all other pts (p=0.02), and were 1.8 times more likely to have VTE than non-Ph ALL pts (p=0.007). Caucasian pts or those with history of prior VTE had a significantly higher incidence of VTE (p=0.03 and p=0.002, respectively). The risk was 2 fold higher for Caucasians and 12 fold higher for those with a prior history of VTE. At the time of VTE, platelet counts were below 50 x 109/L in 33%, 50–100 x 109/L in 10%, and greater than 100 x 109/L in 57%. VTE occurs in a significant proportion of pts with ALL, BL, and LL. Thrombocytopenia does not preclude the development of VTE. Older age, Ph positivity, race, and history of prior VTE were significantly associated with the development of VTE. Further analysis of other known risk factors such as the use of erythropoiesis-stimulating agents, hormonal therapy, and other comorbidities is underway to better refine the subpopulation at risk.

Author notes

Disclosure: No relevant conflicts of interest to declare.