Clinical characteristics and 3-month outcomes in cancer patients with incidental versus clinically-suspected and confirmed pulmonary embolism.

Background Current guidelines suggest treating cancer patients with incidental pulmonary embolism (PE) similar to those with clinically-suspected and confirmed PE. However, the natural history of these presentations has not been thoroughly compared. Methods We used the data from the RIETE registry to compare the 3-month outcomes in patients with active cancer and incidental PE versus those with clinically-suspected and confirmed PE. The primary outcome was 90-day all-cause mortality. Secondary outcomes were PE-related mortality, symptomatic PE recurrences and major bleeding. Results From July 2012 to January 2019, 946 cancer patients with incidental asymptomatic PE and 2274 with clinically-suspected and confirmed PE were enrolled. Most patients (95% versus 90%) received low-molecular-weight heparin therapy. During the first 90 days, 598 patients died, including 42 from PE. Patients with incidental PE had a lower all-cause mortality rate than those with suspected and confirmed PE (11% versus 22%; odds ratio [OR]: 0.43; 95%CI: 0.34-0.54). Results were consistent for PE-related mortality (0.3% versus 1.7%; OR: 0.18; 95% CI: 0.06-0.59). Multivariable analysis confirmed that patients with incidental PE were at lower risk to die (adjusted OR: 0.43; 95%CI: 0.34-0.56). Overall, 29 patients (0.9%) developed symptomatic PE recurrences, and 122 (3.8%) had major bleeding. There were no significant differences in PE recurrences (OR: 0.62; 95%CI: 0.25-1.54) or major bleeding (OR: 0.78; 95%CI: 0.51-1.18). Conclusions Cancer patients with incidental PE had a lower mortality rate than those with clinically-suspected and confirmed PE. Further studies are required to validate these findings, and to explore optimal management strategies in these patients.