Prognostic factors for metastatic renal cell carcinoma patients with removed metastases: A multicenter study of 559 patients.

e15071 Background: Metastasectomy considered to prolong survival in patients with metastatic renal cell carcinoma (mRCC). However, data on the indications for metastasectomy are limited. We aimed to examine the prognosis and the prognostic factors of mRCC patients who underwent metastasectomy. Methods: We sent questionnaires to Japanese hospitals and collected the data of patients who were diagnosed with mRCC between January 1988 and December 2009 and who had their metastatic lesions removed. We calculated the overall survival between metastasectomy and death or until the last follow-up. We also analyzed the relationship between survival and clinical features and identified adverse prognostic factors by multivariate analysis. Furthermore, we identified the group with a poor prognosis on the basis of the number of prognostic factors for which the patients were positive. These findings were internally validated using bootstrap procedures and the c-index. Results: We collected the data of 559 patients from 48 institutions. The median overall survival period was 80 months (95% CI, 69.7-90.6 months). We detected 5 adverse prognostic factors: incomplete resection by metastasectomy (hazard ratio, 1.75; p = 0.0169); brain metastasis (hazard ratio, 3.26; p = 0.0002); C-reactive protein levels of >1.0 mg/dl (hazard ratio, 2.84; p < 0.0001); Eastern Cooperative Oncology Group performance status of >1 (hazard ratio, 1.65; p = 0.0274); and the worst nuclear grade, i.e., the nuclei of tumor cells are larger than those of normal tubular cells (hazard ratio, 1.59; p = 0.0348). Patients positive for 3 or more of theseadverse prognostic factors had a worse prognosis (median overall survival, 24 months) than those positive for less than 3 factors (median overall survival, 105 months). The c-index for this model was 0.65 at 2 years. Conclusions: We identified 5 adverse prognostic factors for predicting the survival of patients who underwent metastasectomy.