Incidental pulmonary embolism in oncology patients with current macroscopic malignancy: incidence in different tumour type and impact of delayed treatment on survival outcome

To evaluate the incidence and outcome of incidental pulmonary embolism (iPE) in patients with current macroscopic malignancy and delayed anticoagulation due to late reporting of CT scan. Reports of CT thorax with i.v. contrast done on oncology patients between 1 January 2015 and 31 December 2015 in two district general hospitals in UK were reviewed. Electronic patient records of iPE patients were reviewed for demographic and treatment information. 26 iPEs were reported in 1,604 scans (731 patients), incidence 1.6%; female = 15; median age = 66 (range 32-90); main artery = 10; lobar artery = 8; segmental = 7; subsegmental = 1; median time (range) from scan to reporting = 1 day (0-60); scan to anticoagulation = 5 days (0-61) (three had no treatment); scan to death = 7 months (1-22+) with nine still alive and two lost to follow up. All had metastatic disease. There was no sudden death. None of the patients whose anticoagulation started more than 5 days after the iPE CT scan died within 3 months. iPE was absent in all repeat staging CT scans (done average 3.4 months after the anticoagulation) in 16 patients, without any anticoagulation in one patient with segmental iPE. Incidence of iPE in patients with current macroscopic malignancy is low-1.6%-mostly seen in lung, breast and colorectal cancer probably due to frequency of imaging. A few days' delay in anticoagulation does not appear to have an impact on the risk of sudden cardiac death. Advances in knowledge: This study tells us that iPE is infrequent, that it can be treated appropriately with anticoagulation, but this does not necessarily need to begin on the same day of diagnosis.