High expression of APRIL correlates with poor prognosis in clear cell renal cell carcinoma

The members of the Tumor Necrosis Factor Superfamily (TNFSF), including A PRoliferation Inducing Ligand (APRIL), have been studied in RCC and other tumors. In this study, we investigated the expression of APRIL in resected clear cell renal cell carcinoma (CCRCC) samples by immunohistochemistry (IHC) and analyzed its association with the clinicopathologic characteristics and prognosis of the patients.

We examined 206 CCRCC samples from patients who underwent radical or partial nephrectomy at Seoul National University Hospital between 1999 and 2002. Tissue microarray (TMA) blocks were made, and immunohistochemical staining for APRIL expression was performed.

We classified the IHC results as high expression or low expression. Of the 206 cases, 89 cases (43.2%) were classified as showing high expression, and 117 cases (56.8%) showed low expression. The high expression of APRIL was significantly correlated with higher Fuhrman nuclear grade and higher pathologic stage (p=0.000 and 0.004), and we observed that the high expression of APRIL was significantly correlated with the overall survival of the patients (p=0.045) and cancer-specific survival (p=0.020), but was not correlated with disease-free survival (p=0.106). In multivariate analysis adjusted for Fuhrman nuclear grade and pathologic stage, the high expression of APRIL was not an independent prognostic factor for CCRCC, as determined by overall survival (p=0.830) and cancer-specific survival (p=0.792).

We found that the high expression of APRIL in CCRCCs was correlated with high Fuhrman nuclear grade, high pathologic stage, and poor overall and cancer-specific survival of the patients. However, it did not correlate with disease-free survival and was not an independent prognostic factor.