Is Routine Chest X-ray Useful in Detection of Pulmonary Metastases after Curative Resection for Colorectal Carcinoma?

ABSTRACT

PURPOSE: This study was performed to evaluate the effectiveness of conventional chest radiography and abdominal CT for early detection of pulmonary metastases after curative surgery for colorectal cancer. METHODS: We retrospectively reviewed 138 cases of pulmonary metastases from a group of colorectal-cancer patients, who were recruited from 1994 to 2002 at Samsung Medical Center, Sungkyunkwan University School of Medicine, and who had been surgically treated with a curative resection. RESULTS: The detection rates for pulmonary metastases were 34.1% by conventional chest radiography, 50.0% by abdominal CT, and 15.9% by other means. For stage I and II tumors, conventional chest radiography was superior to abdominal CT (45.7% vs. 34.3%, P<0.05) for detecting pulmonary metastases. On the contrary, for stage III tumors, abdominal CT was superior to conventional chest radiography (55.3% vs. 30.1%, P<0.05). Compared with stage I and II, pulmonary metastases in stage III had a tendency to be more numerous, bilateral, and extra-pulmonary. They also had a low detection rate by conventional chest radiography and a higher detection rate by abdominal CT, and they were associated with poor survival. CONCLUSIONS: Conventional chest radiography is no more useful in detecting early pulmonary metastases after curative colorectal surgery than abdominal CT, especially for stage III tumors. We propose the use of routine chest CT or extended abdominal CT for screening of occult lung metastases in stage III colorectal cancer patients.