Unsuspected pulmonary embolism: impact on mortality among cancer patients

Symptomatic pulmonary embolism is associated with significant morbidity and mortality, but whether the same is true of unsuspected pulmonary embolism (UPE) has only recently become the subject of clinical research. Interest in the impact of UPE on patient outcomes has emerged, as their detection has become more common with the standard use of multirow detector computed tomography scans. Serial CT scanning of patients with cancer, in conjunction with a higher incidence of venous thromboembolism, makes UPE the most frequent in this population. This review will explore the recent studies which evaluate the impact of UPE on outcomes, especially mortality, among patients with cancer.

Several recent studies have attempted to explore the impact that UPE has on cancer patients, mainly with respect to mortality. These studies have all been retrospective and most have used as a comparator cancer patients with suspected pulmonary embolism based on suggestive symptoms. Regardless, the findings in all but one study conclude that UPE adversely impacts survival among cancer patients, even with proper anticoagulation. However, unsuspected subsegmental pulmonary embolism may not impact survival, regardless of the treatment.

Recent data suggest that cancer patients who develop UPE have mortality rates as well as bleeding rates that parallel those of cancer patients in whom pulmonary embolism is detected on dedicated scans performed because of the presence of pulmonary embolism-related symptoms. Cancer patients who are truly asymptomatic, based on careful screening, may have improved survival, although no prospective studies support definitive treatment recommendations for this group.