Significance of follow-up in detection of pulmonary metastasis of colorectal cancer

Purpose: This study was performed to evaluate the effectiveness of conventional chest radiography, carcinoembrionic antigen (CEA) level and abdominal computed tomography (CT) or chest CT for early detection of pulmonary metastasis after a curative resection of colorectal cancer. Methods: We retrospectively reviewed 84 cases of pulmonary metastasis from a group of colorectal cancer patients who had a curative surgical resection from 2000 to 2006 at the Korea University Medical Center. Results: Stage I tumors were detected in 4 patients, stage II tumors in 18, stage III tumors in 43 and stage IV tumors in 19. The detection rates for pulmonary metastasis were 28.5% by conventional chest radiography, 40.5% by increased CEA level and 28.5% by abdominal CT or chest CT. Among them, fourteen patients underwent a radical pneumonectomy. After detection of pulmonary metastasis, the survival outcome for the patients who underwent a resection of the lung was superior to the survival outcome of the patients who did not undergo a resection of the lung (43.7 months vs. 17.4 months, P = 0.001). For patients who underwent resections of the lung, pulmonary metastasis was detected by conventional chest radiography in 2 (14%) patients, by elevated CEA level in 6 (42%) patients, and by abdominal CT or chest CT in 6 (42%) patients. Conclusion: Conventional chest radiography is no more useful in detecting early pulmonary metastasis after a curative colorectal surgery than a routine chest CT. Thus, we propose the use of routine chest CT for screening for lung metastasis.