The impact of histology on clinicopathologic outcomes for patients with renal cell carcinoma and venous tumor thrombus: a matched cohort analysis.

OBJECTIVE: To evaluate the impact of tumor histology on clinicopathologic outcomes for patients with renal cell carcinoma (RCC) and venous tumor thrombus (VTT).

METHODS: We identified 807 patients with RCC and VTT who underwent nephrectomy at our institution between 1970 and 2008. All pathologic specimens were re-reviewed by a single urologic pathologist. Patients with non-clear cell RCC (non-ccRCC, n = 56) were matched 1:2 to patients with clear cell RCC (ccRCC) VTT based on symptoms at presentation, regional lymph node involvement, distant metastases, tumor thrombus level, nuclear grade, and sarcomatoid differentiation. Survival was estimated using the Kaplan-Meier method and compared with the log-rank test.

RESULTS: The 56 patients with non-ccRCC VTT included 26 papillary, 11 chromophobe, 5 collecting duct tumors, and 14 RCCs not otherwise specified. Compared to unmatched patients with ccRCC VTT (n = 751), patients with non-ccRCC VTT presented with larger tumor size (P = .02), higher nuclear grade (P = .04), and more frequent sarcomatoid differentiation (P <.001) and lymph node invasion (P <.001). However, when patients with non-ccRCC were matched to patients with ccRCC, no significant differences were noted with regard to 5-year metastases-free survival (41% vs 34%, P = .24) or cancer-specific survival (25% vs 27%, P = .97).

CONCLUSION: Non-ccRCC VTT is associated with a high rate of adverse pathologic features. Nevertheless, when matched to patients with ccRCC, patients with non-ccRCC VTT did not have increased rate of recurrence or adverse survival. Aggressive surgical resection represents the mainstay of treatment in these cases, whereas continued efforts to optimize a multimodal management approach to such patients remain necessary.