Body CT in unprovoked PE – a worthwhile fishing trip?

Abstract

Purpose Cancer and pulmonary embolism (PE) have an established causal relationship but there is a paucity of data on the incidence of occult cancer in patients with PE and no other risk factors. The National Institute of Health and Care Excellence (NICE) guidelines recommend further investigation with abdomino-pelvic computed tomography (CT AP) increasing demand on radiology departments. We aimed to determine if this is an appropriate use of resources by ascertaining occult cancer prevalence, type and stage at diagnosis in such cases. Methods and materials Patients with unprovoked PE diagnosed on CTPA and who subsequently had CT AP were identified from the radiology information system (RIS)/picture archiving and communication system (PACS) for the two-year period January 2013 to December 2014. The following were recorded: age, sex, diagnosis of a cancer, and if present the type and stage. Results Of patients with a positive CTPA and subsequent CT AP, 7.4% had occult cancers (ten cancers in 135 patients). The detected cancers were pancreatic, colonic, bladder, prostate, hepatic, pelvic soft tissue sarcoma and haematological. Of these, 70% were locally advanced or metastatic cancers. Age range: 64–92. No specific factors were identified to enable risk stratification of these patients. Conclusion Occult cancers in patients with PE are often advanced with a poor two-year survival rate. However, a small proportion are treatable and investigation in PE patients with no provoking factors should be considered. No risk factors are identified to risk stratify the cancer detection scans.