Resection of pulmonary metastases from colon and rectal cancer: factors to predict survival differ regarding to the origin of the primary tumor.

BACKGROUND: The purpose of the present study was to determine differences in prognostic factors for survival of patients with pulmonary metastases resected in curative intent from colon or rectum cancer.
METHODS: Between 1980 and 2006, prognostic factors after resection of pulmonary metastases in 171 patients with primary rectum or colon tumor were evaluated. Survival of patients after surgical metastasectomy was compared with that of patients receiving standard chemotherapy by matched-pair analysis.
RESULTS: Median survival after pulmonary resection was 35.2 months (confidence interval 27.3-43.2). One-, 3-, and 5-year survival for patients following R0 resection was 88.8, 52.1, and 32.9 % respectively. Complete metastasectomy (R0), UICC stage of the primary tumor, pleural infiltration, and hilar or mediastinal lymph node metastases are independent prognostic factors for survival. Matched-pair analysis confirmed that pulmonary metastasectomy significantly improved survival. Although no difference in survival for patients with pulmonary metastases from lower rectal compared to upper rectal or colon cancer was observed, factors to predict survival are different for patients with lower and middle rectal cancer (R0, mediastinal and/or hilar lymph nodes, gender, UICC stage) compared with patients with upper rectal or colon cancer (R0, number of metastases).
CONCLUSIONS: Our results indicate that distinct prognostic factors exist for patients with pulmonary metastases from lower rectal compared with upper rectal or colon cancer. This supports the notion that colorectal cancer should not be considered as a single-tumor entity. Metastasectomy, especially after complete resection resulted in a dramatic improvement of survival compared with patients treated with chemotherapy alone.