Purpose: Although outcome of resection for colorectal carcinoma has improved, about 30 percent of patients develop metastatic lesions. Small pulmonary metastases 1 cm or less in diameter now can be detected by diagnostic tests including chest radiography and computed tomography. We evaluated results of our strategy for intensive follow-up after resection of colorectal cancer and aggressive resection of lung metastases disclosed by these periodic examinations.
Methods: Our follow-up program for lung metastasis includes a serum carcinoembryonic antigen assay every two months and chest radiography every six months. Surgical resection of lung metastases was performed if the primary and any nonpulmonary metastases had been controlled, lung metastases numbered four or fewer, and pulmonary functional reserve was adequate. Standard operation for lung metastasis was lobectomy, and lymph node dissection was added in cases of tumor size over 3 cm. Forty-two patients underwent 50 lung resections for metastatic colorectal cancer between 1992 and 1999. Long-term survival was assessed in terms of clinical variables.
Results: Overall five-year survival rate after resection of lung metastases from colorectal cancer was 63.7 percent. Variables significantly affecting postthoracotomy survival were primary tumor histology, number of nodules, and disease-free interval up to appearance of the lung metastases, and primary tumor histology was an independent prognostic factor.
Conclusion: Intensive follow-up for lung metastases after resection of colorectal cancer and aggressive resection improved postoperative survival rate. Patients with well-differentiated adenocarcinoma of primary tumor, a solitary metastatic nodule, and disease-free interval of at least two years after initial surgery are likely to be long-term survivors.