Rates of initial and recurrent thromboembolic disease among patients with malignancy versus those without malignancy. Risk analysis using Medicare claims data.

Although the association between malignancy and thromboembolic disease is well established, the relative risk of developing initial and recurrent deep vein thrombosis (DVT) or pulmonary embolism (PE) among patients with malignancy versus those without malignancy has not been clearly defined. The Medicare Provider Analysis and Review Record (MEDPAR) database was used for this analysis. Patients hospitalized during 1988-1990 with DVT/PE alone, DVT/PE and malignancy, malignancy alone, or 1 of several nonmalignant diseases (other than DVT/PE) were studied. The association of malignancy and nonmalignant disease with an initial episode of DVT/PE, recurrent DVT/PE, and mortality were analyzed. The percentage of patients with DVT/PE at the initial hospitalization was higher for those with malignancy compared with those with nonmalignant disease (0.6% versus 0.57%, p = 0.001). The probability of readmission within 183 days of initial hospitalization with recurrent thromboembolic disease was 0.22 for patients with prior DVT/PE and malignancy compared with 0.065 for patients with prior DVT/PE and no malignancy (p = 0.001). Among those patients with DVT/PE and malignant disease, the probability of death within 183 days of initial hospitalization was 0.94 versus 0.29 among those with DVT/PE and no malignancy (p = 0.001). The relative risk of DVT/PE among patients with specific types of malignancy is described. This study demonstrates that patients with concurrent DVT/PE and malignancy have a more than threefold higher risk of recurrent thromboembolic disease and death (from and cause) than patients with DVT/PE without malignancy. An alternative management strategy may be indicated for such patients.

Factors influencing the oxidation of the radioprotector WR-1065.

N-(2-Mercaptoethyl)-1,3-diaminopropane (WR-1065) is the free thiol form of the radio- and chemoprotector S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721). Interest currently exists in the clinical use of WR-2721 and WR-1065 as radio- and chemoprotectors of normal tissues. However, measurement of plasma levels of WR-1065 has proven difficult, due to rapid drug oxidation. Therefore, we studied factors influencing the oxidation of WR-1065, in Hepes-buffered saline as well as in tissue culture media containing 10% fetal bovine serum. The rate of oxygen consumption by WR-1065, as determined using the Clark oxygen electrode system, was faster in medium plus serum than in Hepes-buffered saline. That this effect is largely due to the presence of trace metal ions in tissue culture media and serum was indicated by the observation that addition of Cu2+ or Fe3+ to buffer stimulated oxygen consumption. Addition of KCN inhibited the reaction of WR-1065 with oxygen, and this effect was dependent on KCN concentration. That KCN blocked WR-1065 oxidation to the disulfide was verified using Ellman's reagent to quantitate the free thiol form. The rate of oxygen consumption was shown to be affected by temperature as well as concentration of WR-1065. Catalase reduced the rate of oxygen consumption of WR-1065, indicating that peroxide is formed in this system. Superoxide dismutase had a stimulatory effect. WR-1065 was found to stimulate the hexose monophosphate shunt in A549 cells. Since this stimulation was prevented by the presence of catalase, it appeared to be due to the response of the cells to peroxide, formed as a result of WR-1065 autooxidation.

Delayed, transient encephalopathy after marrow transplantation: case reports and MRI findings in four patients.

Subacute encephalopathy developed in four patients within one to two months after undergoing high-dose chemotherapy and bone marrow transplantation or peripheral blood progenitor (stem) cell transplantation for breast cancer, acute myeloid leukemia, and non-Hodgkin's lymphoma. None of the patients had previously known neurologic disorders, central nervous tumor or infection. Two patients presented with generalized tonic, clonic seizures, and two with confusion and lethargy. In all patients lumbar puncture and CT scans of the brain were normal, while magnetic resonance imaging (MRI) demonstrated multifocal predominantly white matter lesions. Phenytoin therapy was given to the two patients with seizures and all four patients improved without specific therapeutic intervention. Repeat MRIs became normal within three months. We report a delayed and transient encephalopathy which appears to be a unique complication of high-dose cytotoxic chemotherapy. The corresponding brain lesions may not be appreciated on CT scans, suggesting an expanded role for MRI studies in patients who develop neurologic findings while undergoing high-dose cytotoxic therapy.