Purpose: To our knowledge the benefit of cytoreductive surgery for patients with metastatic renal cell carcinoma with nonclear cell histology is unknown. In this retrospective study we report our experience with cytoreductive nephrectomy for nonclear cell metastatic renal cell carcinoma at M. D. Anderson Cancer Center. We compared the outcomes with those in patients with clear cell metastatic renal cell carcinoma.
Materials and methods: From 1991 to 2006, 606 patients with metastatic renal cell carcinoma underwent cytoreductive nephrectomy and they formed the basis of this report. Of these patients 92 had nonclear cell metastatic renal cell carcinoma. The remaining 514 patients had clear cell metastatic renal cell carcinoma and they formed a comparative group. Multivariate Cox regression analysis was performed to evaluate the relationship between clinical variables and histology (clear cell vs nonclear cell) on disease specific survival.
Results: Compared with patients with clear cell histology those with nonclear cell metastatic renal cell carcinoma were younger (p = 0.0001), and more likely to have nodal metastases (p <0.0001) and sarcomatoid features (23% vs 13%, p = 0.026). On multivariate analysis median disease specific survival in patients with nonclear cell histology was significantly worse than that in patients with clear cell metastatic renal cell carcinoma (9.7 vs 20.3 months, p = 0.0003) even after adjusting for T stage, grade, performance status, age and sarcomatoid features. Sarcomatoid features were a predictor of poor outcome in cases of clear and nonclear cell histology, although even in the absence of sarcomatoid features nonclear cell histology was associated with worse disease specific survival (p = 0.017). Interestingly although there was a significantly higher incidence of positive nodes in patients with nonclear histology (p <0.0001), this phenotype was not associated with a worse disease specific survival, as it was in those with clear cell histology (p = 0.0001). In fact, patients with node negative disease with nonclear cell histology had the worst prognosis overall in the entire group.
Conclusions: Patients with nonclear cell metastatic renal cell carcinoma were younger and had a higher incidence of nodal metastases, a higher incidence of sarcomatoid features and a worse prognosis than those with clear cell histology who underwent cytoreductive surgery.