Can We Predict Long-Term Survival After Pulmonary Metastasectomy for Renal Cell Carcinoma?

Background The purpose of this study is to identify factors associated with time-related survival after pulmonary metastasectomy for renal cell carcinoma and to confirm the safety of metastasectomy. Methods From January 1986 to July 2001, 417 patients were diagnosed with pulmonary metastases from renal cell carcinoma; 92 underwent pulmonary metastasectomy. Median disease-free interval after nephrectomy was 3.0 years. Half the patients had 1 or 2 pulmonary nodules; 37% had 5 or more. Median size of the largest nodule (pulmonary metastasis) was 15 mm. Complete resection was obtained in 63 patients (68%). Twenty-nine patients received preoperative immunotherapy. Multivariable hazard function analysis was used to identify continuous, ordinal, and true dichotomous risk factors. Results Predictors: The strongest risk factor for time-related mortality was incomplete resection. Five-year survival was 8% for incomplete and 45% for complete resection. Other risk factors included the following continuous and ordinal variables: larger nodule size (p = 0.0001), increasing number of involved lymph nodes (p = 0.01), and decreased preoperative 1-second forced expiratory volume (p = 0.02). Immunotherapy did not improve survival. For completely resected patients, shorter disease-free interval was a risk factor (p = 0.01). Fewer pulmonary nodules predicted higher probability of complete resection (p< 0.0001). Safety: No operative deaths occurred. Nine patients (10%) experienced a total of 12 complications, with persistent air leak and atrial arrhythmia accounting for 5 (42%). Conclusions Because pulmonary metastasectomy for renal cell carcinoma is safe, survival depends on complete resection of pulmonary disease and adequate pulmonary reserve. Preoperative determination of resectability is thus critical, and computed chest tomography and mediastinoscopy are valuable tools for optimizing patient selection.