Staging Rectal Cancer: The Utility of Chest Radiograph and Chest Computed Tomography

The National Comprehensive Cancer Network recommends that patients who are newly diagnosed with rectal cancer undergo staging CT scan of the chest. It is unclear whether posteroanterior and lateral chest radiography (X-ray) alone would provide adequate staging for most of these patients. A retrospective review was performed on all patients who had a two-view chest X-ray along with a chest CT for rectal cancer staging from 2007 to 2015. A total of 74 patients had both modalities. Sixty-three (85%) had a normal chest X-ray and 11 (15%) had an abnormal chest X-ray. Of the 63 patients with a normal chest X-ray, 40 (63%) had a corresponding normal chest CT and 23 (37%) had a lesion only noted on chest CT. Four patients (17%) in the latter group had metastatic cancer to the lung at the time of workup and four out of five of the tumors found to metastasize were within 5 cm from the anal verge. Our data suggest that a staging chest X-ray is unlikely to diagnose metastatic lungs lesions from a primary rectal cancer. Conversely, staging chest CT will accurately stage metastatic disease but will also reveal benign lung lesions in this patient population.