The diagnostic yield of preoperative staging computed tomography of the thorax in colorectal cancer patients without hepatic metastases.

BACKGROUND: National UK guidelines recommend preoperative computed tomography (CT) examination of the chest for all patients with colorectal cancer (CRC) as identification of thoracic metastatic disease may influence treatment plans. The diagnostic yield of this approach for patients without radiological evidence of hepatic metastases remains unclear. The aim of this study was to establish the impact upon treatment of chest CT examination for CRC patients without metastatic liver disease.

PATIENTS AND METHODS: All patients diagnosed with CRC without liver metastases disease between December 2006 and December 2013 in a single institution were identified from a prospectively recorded departmental database. Data collected included patient demographics, disease stage and chest CT findings.

RESULTS: There were 358 CRC patients (183 male, 175 female, median age 70 years, range 24-96 years) without liver metastases. Colon cancer accounted for 68% of cases with 32% of patients diagnosed with rectal cancer. The majority of patients (n=292, 81.6%) had no evidence of thoracic pathology during the study period. Lung metastases were identified in five (1.4%) patients, one of them subsequently diagnosed with benign pulmonary nodule. In 61 (17.0%) patients the lung nodules were classified as intermediate with only three subsequently reclassified as pulmonary metastases (n=1) or primary lung cancer (n=2).

CONCLUSION: In the absence of liver metastases, CRC rarely spreads to the lung. Consequently, preoperative chest CT examination for patients without evidence of liver metastases may not be necessary in the majority of patients. Future studies are required to identify patients at high risk for pulmonary metastases who may benefit from this preoperative investigation.