Histologic tumor necrosis rate as a predictor of recurrence after surgical treatment for localized clear cell renal cell carcinoma
Abstract
INTRODUCTION: Coagulative tumor necrosis (TN) is a potential negative prognostic marker in clear cell renal cell carcinoma (ccRCC). Our study assessed the significance of the TN rate in histological specimens in terms of the risk of recurrence in patients after surgical treatment for localized disease.
METHODS: Our study included 149 subjects surgically treated for ccRCC from 2011 to 2014. Mean postoperative follow-up was 538 days.
Presence of TN was assessed by a physician - pathologist in histological specimens. The following findings were described: without necrosis (79 samples), TN rate below 50% (46 samples) and TN rate higher or equal to 50% of the specimen (24 samples).
The Kaplan-Meier method, log-rank test and Cox regression analysis were used to evaluate the disease-free survival (DFS). RESULTS: Seventeen patients experienced recurrence - with no TN detected in 3, TN rate below 50% in 6 and TN rate above 50% in 8 patients.
There was a significant difference in DSF in patients with proven TN compared to patients without TN (HR 3.83; CI95% 1.489.94%; p=0.006; in multivariate analysis: p=0.031). Evaluation according to the proportion of TN showed a significant difference in DFS in patients with the TN rate below or equal to 50% compared to patients without TN (HR 16.27; CI95% 4.0066.15; p=0.0001; in multivariate analysis: p=0.041).
The difference of DSF between patients without TN and with the TN rate higher than 50%, and patients with the TN rate below 50% and higher than 50% was not statistically significant. CONCLUSION: Our study confirmed TN as a risk factor of disease recurrence.
Additionally, a higher TN rate is associated with a significantly higher risk of recurrence.