CLO20-067: Clinical Characteristics, Management and Outcome of Incidental Pulmonary Embolism in Cancer Patients: A Case-Control Study

Incidental pulmonary embolisms (IPE) are commonly discovered in cancer patients during their cancer staging and surveillance imaging studies. Examining the clinical characteristics and outcomes of these incidents in cancer patients may guide the proper management of those IPEs, further promoting better outcomes. To determine the clinical characteristics, management and outcomes of IPE for cancer patients presenting to the emergency department, we conducted 1:2 ratio case-control study and identified all consecutive cases of IPE who visited the emergency department of The University of Texas MD Anderson Cancer Center between January 1, 2006, and December 31, 2015. For each reviewed confirmed case, two cancer patients without IPE who matched a case on CT scan date, age, gender, race, cancer type, cancer stage, Charlson comorbidity index, renal function, and payer/insurance type were identified. The final cases and their matched controls were further reviewed and analyzed. Among 999 eligible cases identified, 904 were confirmed as final cases and included in the analysis. IPE tend to frequently occur during the first year after cancer diagnosis (OR=2.79 [95%CI: 2.37-3.29], P<0.001). Patients on active treatment with cytotoxic chemotherapy had almost three times higher risk of developing IPE compared to patients without active treatment (OR=2.87 [95%CI: 2.42-3.40], P<0.001). Five hundred seventy-four of the IPE cases (63.5%) were discharged home. The majority (83.2%) of the cases were initially treated with Low-molecular-weight heparins. Eighty (8.8%) patients had no initial treatment. Upon admission, in-hospital mortality was 1.9% (17 patients). Concurrent incidental VTE was identified in 189 (20.9%) of the patients. The 7, 30- and 90-days mortality among the cases were 16 (1.8%), 90 (9.9%) and 201 (22.1%) respectively, which was significantly higher than the 3 (0.2%), 56 (3.1%) and 179 (9.8%) for the control group (all P<0.001). The incidence of IPE was significantly associated with shorter overall survival (HR= 1.93 [95%CI: 1.74-2.14], P<0.001). The presence of concurrent central VTE poorly affected overall survival (HR= 1.65 [95%CI: 1.21-2.25], P=0.001) In conclusion, IPE events are associated with poor outcomes in cancer patients. Proper management plans similar to those of symptomatic pulmonary embolisms are essential.