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

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.

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.

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.

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.