The availability of computed tomography for pulmonary staging in colorectal cancer

Purpose: Chest computed tomography is performed frequently for the preoperative pulmonary staging in colorectal cancers (CRCs) regardless of the result of chest x-ray (CXR) due to its high sensitivities and specificities. The advancement of CT technology detects more indeterminate lung lesions that may require further investigations, referrals and follow-up. The aim of this study was to suggest a guideline for performing chest CT for preoperative pulmonary staging in colorectal cancer. Methods: We performed a retrospective analysis of the records of patients who had chest CT preformed without the evidence of metastasis on CXR for preoperative pulmonary staging. Results: Of 21 patients with metastatic nodules on chest CT, 23.8% showed pulmonary metastasis on positron emission tomography, 47.6% showed extrapulmonary metastasis on preoperative evaluation and 61.9% showed elevated serum carcinoembryonic antigen level above 10 ng/mL. These results showed significant value compared to patients without metastatic nodules. But, in analyzing patients with or without indeterminate nodules in the three contents listed above, there was no significance. Conclusion: In the patients with CRC who show normal CXR and exhibit positivity in PET, preoperative extrapulmonary metastasis and elevated serum CEA level above 10 ng/mL preoperatively, chest CT would be helpful in preoperative staging.