Renal cell carcinoma lung metastases surgery: Pathologic findings and prognostic factors

Background. Renal cell carcinoma metastases are more frequently located in the lungs, with surgical results better than in other anatomic locations. Prognosis is darkened by incomplete resection, short disease-free interval, and number of lung metastases (LM). Our purpose was to further review these prognostic factors and related renal cell carcinoma disease characteristics. Methods. From 1984 to 2005, 65 consecutive patients underwent surgery for LM in view of cure. Studied factors were age, sex, smoking habits, forced expiratory volume in 1 second, disease-free interval, adjuvant therapy, size and number of metastases, lymph node involvement, and renal cell carcinoma pathologic staging. These factors were compared with those of 23 patients with previously resected renal cell carcinoma and undergoing surgery for lung cancer during the same period. Results. There were 44 unilateral and 21 bilateral LM; 83 operations were performed, with no postoperative deaths. Lung metastases were classified in four subgroups: single metastasis ( n = 23), multiple unilateral metastases ( n = 8), LM and other organ metastasis ( n = 13), and bilateral LM ( n = 21). Five- year overall survival ( 37.2% when resection was complete) was not statistically different among subgroups nor dependent on age, sex, smoking, forced expiratory volume in 1 second, disease-free interval, and adjuvant therapy, but was significantly influenced by the size of LM and lymph node involvement (univariate and multivariate analyses). Lymph node involvement was less frequent than in patients operated on for lung cancer: respectively, 13 of 65 (20%) and 13 of 23 (56.5%; p = 0.0009). Intrathoracic metastatic spread was not related to a particular renal cell carcinoma pathologic tumor staging (pT) subgroup. Conclusions. Size of LM and lymph node involvement are important prognostic factors. They suggest a metastatic mode of spread involving the renal lymphatic drainages and specific biologic characteristics acquired by selected tumor cells.