Steven R. Deitcher, MD

The two-part article, "ThromboembolicComplications ofMalignancy," by Drs. Linenbergerand Wittkowsky, provides a contemporaryand clear review of thepathogenesis, prevention, and treatmentof cancer-associated hypercoagulabilityand venous thrombosis. Questionsabout the cancer and coagulation connectioncontinue to abound and greatlyoutnumber evidence-based answers. Asthe relationship between cancer and coagulationgains attention from the medicaland surgical oncology communities(ie, not only from the coagulation community),the gap between questions andanswers will likely close.

Venous thromboembolic disease is a common but likely underdiagnosedcondition in the cancer patient population. Timely and accuratediagnosis of venous thromboembolism is imperative due to the unacceptablemorbidity and mortality associated with a misdiagnosis.Because diagnosis of the condition based on clinical grounds alone isunreliable, physicians should select an appropriate objective diagnostictest to confirm or refute their clinical impressions. Compressionduplex ultrasound is the best initial imaging test for both suspectedupper- and lower-extremity deep venous thrombosis. Magnetic resonancevenography (MRV) is a valid alternative when ultrasound isinconclusive, but contrast venography remains the “gold standard.”Suspected pulmonary embolism should be initially evaluated by helical(spiral) computed tomography (CT) or ventilation/perfusion lungscintigraphy, the former being preferred in cases of obvious pulmonaryor pleural disease. Indeterminate studies should prompt performanceof contrast pulmonary angiography. Inferior vena cava thrombosis isalso best assessed by contrast venography, with MRV and CT reservedas alternative imaging modalities. Evidence to date suggests thatD-dimer assays remain unreliable in excluding venous thromboembolismin cancer patients. A newer latex agglutination D-dimer assay mayprove to be clinically useful in this setting.

Drs. Goodnough and DiPersio should be commended for contributing such a well-written, well-referenced, objective, and authoritative review of issues in the management of cancer-related thrombocytopenia. Their article focuses primarily on platelet transfusion risks, rational transfusion thresholds, and potential novel pharmaceutical triumphs. The general lack of large-scale, definitive clinical trials in this field is appreciated and emphasized throughout. Much to my disappointment, the authors seem to have passed on the opportunity to provide the oncology community with any form of evidence-based (or evidence-lacking, as the case may be) and practical guideline for the treatment of thrombocytopenia.