Prognostic factors of patients with metastatic renal cell carcinoma with removed metastases: a multicenter study of 556 patients.

Objective To investigate the prognosis and prognostic factors of patients with metastatic renal cell carcinoma who underwent metastasectomy. Methods We sent questionnaires to Japanese hospitals. The questionnaires included data of patients with metastatic renal cell carcinoma who had their metastatic lesions removed between January 1988 and December 2009. We collected them and retrospectively analyzed these data and calculated the overall survival from the first metastasectomy until death or last follow-up. We also analyzed the relationship between survival and clinico-pathologic features and determined adverse prognostic factors. Furthermore, we identified a poor prognostic group by counting the number of prognostic factors. Results A sample size of 556 patients from 48 institutions was studied. The median overall survival was 80 months. Four adverse prognostic factors were detected: incomplete resection by metastasectomy (hazard ratio [HR], 2.15), brain metastasis (HR, 3.73), >1.0 mg/dL C-reactive protein (HR, 2.45), and the highest histologic grade in Japanese classification (nuclei of tumor cells are larger than nuclei of normal tubular cells; HR, 1.88). The median overall survivals of patients with 3 or 4 prognostic factors, 2 factors, and 0 and 1 factors were 10 months, 42 months, and 105 months, respectively. Conclusion Four adverse prognostic factors for predicting the survival of patients with removed metastases were identified. Patients with 3 or 4 of these adverse prognostic factors had a worse prognosis.