Prognostic factors of pulmonary metastasis from colorectal carcinoma.

OBJECTIVES This study was conducted to investigate the prognostic factors of pulmonary metastases, focusing on the time of detection of pulmonary metastases related to adjuvant chemotherapy in patients with colorectal cancer (CRC). METHODS Between June 2003 and December 2010, 84 patients underwent pulmonary metastasectomy for pulmonary metastasis (PM) from CRC. The clinicopathological data of colorectal surgery and pulmonary metastasectomy were analysed retrospectively. Disease-free intervals (DFIs) were specifically classified into the following three groups related to adjuvant chemotherapy after colorectal operation: Group 1, metastasis detected at initial presentation; Group 2, metastasis detected during adjuvant chemotherapy; Group 3, metastasis detected after completion of chemotherapy. The prognostic influence of these variables on disease-free survival was analysed using the log-rank test for univariate analysis and the Cox proportional hazards model for multivariate analysis. RESULTS The median follow-up durations for patients after curative resection of CRC and pulmonary metastasectomy were 48.6 and 28.8 months, respectively. After pulmonary metastasectomy, recurrence was seen in 49 (58.3%) patients-pulmonary recurrence in 37 and extrathoracic recurrence in 12. Young age (<54 years old) at CRC operation, more than one PM, a DFIs of <12 months, detection synchronously or under adjuvant chemotherapy, and high CEA level before metastasectomy were worse prognostic factors by univariate analysis. From multivariate analysis, the number of pulmonary metastases (multiple metastases, HR=2.121, 95% confidence interval 1.081-4.159, P=0.029) and DFIs related with adjuvant chemotherapy (Group 1+2, HR=1.982, 95% confidence interval 1.083-3.631, P=0.027) were found to be independent predictors of disease-free survival. CONCLUSIONS Disease-free intervals in association with the time of adjuvant chemotherapy and number of metastases were independent poor prognostic factors for pulmonary metastases from colorectal cancer.