Surgery for lung metastases from colorectal cancer: analysis of prognostic factors.

PURPOSE: To identify prognostic factors of improved survival after resection of isolated pulmonary metastases (PM) from colorectal cancer.

PATIENTS AND METHODS: A retrospective analysis of the records of all patients with PM from colorectal cancer who underwent thoracic surgery with curative intent before December 1992 at a single surgical center was performed. Univariate (log-rank) and multivariate (Cox's model) analyses of survival were used to identify significant prognostic factors.

RESULTS: Eighty-six patients with PM from colon (n = 49) or rectal (n = 37) cancer underwent 102 thoracic operations, which included 21 bilateral and 10 incomplete resections. The 5- and 10-year probabilities of survival (Kaplan-Meier) after the first thoracic operation were 24% (95% confidence interval [CI], 15% to 35%) and 20% (95% CI, 13% to 31%), respectively. Sex, age, site of the primary tumor (colon or rectum), disease-free interval (DFI), and previous resection of hepatic metastases were found not to be statistically significant prognostic factors. Complete resection, a limited number ( < two) of PM, and a normal prethoracotomy serum carcinoembryonic antigen (CEA) level were predictors of a longer survival duration by univariate analysis, but only complete resection (P = .024) and preoperative CEA level (P = .001) were identified as independent prognostic factors by multivariate analysis. The estimated 5-year survival rate of patients with a normal prethoracotomy CEA level was 60%, as compared with 4% in cases with elevated ( > 5 ng/mL) CEA level.

CONCLUSION: Besides resectability, the prethoracotomy serum CEA level appears the most reliable predictor of survival in patients with isolated PM from colorectal cancer.