Cytoreductive nephrectomy for metastatic renal cell carcinoma in the presence of nonconventional histology

Abstract

14535 Background: While randomized trials show a survival benefit for cytoreductive nephrectomy in the setting of metastatic conventional (clear cell) renal cell carcinoma (mRCC), the benefit of cytoreductive surgery for patients with mRCC of nonconventional histology (papillary, chromophobe, unclassified) is unknown. We evaluated our experience with cytoreductive nephrectomy for nonconventional mRCC at M. D. Anderson. Methods: From 1990–2004, 464 patients with mRCC underwent cytoreductive nephrectomy; of these, 89 patients had nonconventional mRCC and form the basis of this report. The remaining 375 patients with conventional mRCC formed a comparative group. Overall survival (OS) and disease-specific survival (DSS) data were evaluated by Kaplan and Meier analysis, with univariate and multivariate log rank tests. Results: Compared to patients with conventional histology, patients with nonconventional mRCC were younger (p < 0.045), more likely to have nodal metastases (p < 0.0001), and more likely to have sarcomatoid dedifferentiation (21.2 versus 13.2%, p = 0.056). In multivariate analysis, the median survival for nonconventional histology was significantly worse than for conventional mRCC (11.1 versus 19.5 months, p = 0.0081), even after adjusting for stage, grade, performance status, age, and presence of sarcomatoid dedifferentiation. Although positive nodal status was associated with a decreased survival in nonconventional histology (p < 0.0001) in our multivariate analysis, even node negative patients demonstrated a worse survival when compared to those with conventional histology (p = 0.03). Interestingly, patients with nonconventional mRCC who had complete resection of their retroperitoneal nodal metastases with cytoreduction showed a trend towards improved survival, as has been reported in patients with conventional mRCC and nodal disease. Conclusions: Patients with nonconventional mRCC have a higher incidence of nodal metastases and demonstrate a worse prognosis than those with conventional histology, who undergo cytoreductive surgery. Aggressive cytoreduction with removal of all nodal disease may improve outcomes. More effective systemic therapies are needed to improve upon the results seen with aggressive surgery. No significant financial relationships to disclose.