Percent microscopic tumor necrosis and survival after curative surgery for renal cell carcinoma

Purpose: Tumor necrosis is a potential marker of recurrence and survival after surgery for renal cell carcinoma. We determined whether a correlation exists between the amount (not just the presence/absence) of tumor necrosis, and metastasis-free, disease specific and overall survival after surgery for renal cell carcinoma.

Materials and methods: We identified 841 consecutive patients who underwent partial or radical nephrectomy from 1989 to 2004 for renal cell cancer. Specimens were re-reviewed by a single pathologist (MFS). The tumor necrosis percent was none in 586 cases, less than 50% in 198 and 50% or greater in 55. Grade, stage, subtype, size, gender and age were also analyzed. Variables at p <0.05 on univariate analysis were incorporated into a Cox proportional hazards multivariate model. Metastasis-free, disease specific and overall survival was described using the Kaplan-Meier method and compared with the log rank test.

Results: Tumor necrosis was found in 253 specimens (30%). Univariate analysis revealed that the percent and presence of tumor necrosis correlated with metastasis-free, disease specific and overall survival. On multivariate analysis tumor necrosis presence/absence did not remain an independent predictor of disease specific (p = 0.7), metastasis-free (p = 0.7) or overall (p = 0.2) survival. Greater than 50% tumor necrosis was no longer a statistically significant predictor of metastasis-free survival (p = 0.45) but remained significant for disease specific (p = 0.02) and overall (p = 0.01) survival.

Conclusions: The presence of 50% or greater tumor necrosis correlates with worse disease specific and overall survival but not metastasis-free survival in patients with renal cell carcinoma. Results support the inclusion of percent tumor necrosis over the presence/absence of tumor necrosis in the risk assessment of patients who undergo surgical treatment for renal cell carcinoma.