Preoperative staging with chest CT in patients with colorectal carcinoma: not as a routine procedure

Preoperative staging of patients with colorectal carcinoma (CRC) has the potential benefit of altering treatment options when metastases are present. The clinical value of chest computed tomography (CT) in staging remains unclear.

All patients who undergo colorectal surgery in our hospital are prospectively registered, including patient, treatment, and histopathological characteristics; outcome; and follow-up. Since January 2007, routine preoperative staging CT of chest and abdomen for patients with CRC has been performed as part of our regional guidelines. In this observational cohort study, an analysis on outcome was done after inclusion of 200 consecutive patients.

Synchronous metastases were present in 60 patients (30%). Staging chest CT revealed pulmonary metastases in 6 patients, with 1 false positive finding. In 50 patients indeterminate lesions were seen on chest CT (25%). These were diagnosed during follow-up as true metastases (n = 8), bronchus carcinoma (n = 2), benign lesions (n = 25), and remaining unknown (n = 15). Ultimately, synchronous pulmonary metastases were diagnosed in 13 patients (7%), in 6 patients confined to the lung (3%). In none of the patients the treatment plan for the primary tumor was changed based on the staging chest CT.

The low incidence of pulmonary metastases and minimal consequences for the treatment plan limits the clinical value of routine staging chest CT before operation. It has several disadvantages such as costs, radiation exposure, and prolonged uncertainty because of the frequent finding of indeterminate lesions. Based on this study, a routine staging chest CT in CRC patients is not advocated.