Low-grade metastases in high-grade clear cell renal cell carcinomas

Aberrant Expression of E-cadherin, N-cadherin, and P-cadherin in Clear Cell Renal Cell Carcinoma: Association With Adverse Clinicopathologic Factors and Poor Prognosis

OBJECTIVE

Aberrant expression of cadherins is known to be associated with tumor aggression. However, their role in clear cell renal cell carcinoma (CCRCC) is not well elucidated. This study investigated the expression of epithelial cadherin (E-cadherin), neural cadherin (N-cadherin), and placental cadherin (P-cadherin) in CCRCC, and assessed their prognostic significance and clinicopathologic association.

MATERIALS AND METHODS

We enrolled 254 patients with CCRCC who underwent radical or partial nephrectomy. E-cadherin, N-cadherin, and P-cadherin expression was evaluated by immunohistochemistry in a tissue microarray.

RESULTS

Low E-cadherin expression was associated with larger tumor size, lymphovascular invasion, higher pT stage, lymph node and distant metastasis, and higher stage. High N-cadherin expression was significantly associated with larger tumor size, higher nuclear grade, and tumor necrosis. P-cadherin expression was found to be significantly associated with higher nuclear grade, distant metastasis, and higher stage. Univariate analysis revealed that aberrant expression of the 3 cadherins was significantly related to shorter overall survival (OS). Loss of E-cadherin, high P-cadherin expression, and higher stage were independent prognostic factors for OS. For recurrence-free survival, lymphovascular invasion, high P-cadherin expression, and higher stage were independent prognostic factors. Cadherin switch was significantly associated with aggressive clinicopathologic factors and poor outcomes.

CONCLUSIONS

Aberrant expression of E-cadherin, N-cadherin, and P-cadherin was associated with adverse clinicopathologic factors and worse OS. Low E-cadherin and high P-cadherin expression were significantly associated with distant metastasis and independent prognostic factors. Therefore, cadherin expression may be used as a prognostic marker and therapeutic target, and cadherin switch plays an important role in CCRCC progression.

The Impact of Tumor Eco-Evolution in Renal Cell Carcinoma Sampling

Malignant tumors behave dynamically as cell communities governed by ecological principles. Massive sequencing tools are unveiling the true dimension of the heterogeneity of these communities along their evolution in most human neoplasms, clear cell renal cell carcinomas (CCRCC) included. Although initially thought to be purely stochastic processes, very recent genomic analyses have shown that temporal tumor evolution in CCRCC may follow some deterministic pathways that give rise to different clones and sub-clones randomly spatially distributed across the tumor. This fact makes each case unique, unrepeatable and unpredictable. Precise and complete molecular information is crucial for patients with cancer since it may help in establishing a personalized therapy. Intratumor heterogeneity (ITH) detection relies on the correctness of tumor sampling and this is part of the pathologist’s daily work. International protocols for tumor sampling are insufficient today. They were conceived decades ago, when ITH was not an issue, and have remained unchanged until now. Noteworthy, an alternative and more efficient sampling method for detecting ITH has been developed recently. This new method, called multisite tumor sampling (MSTS), is specifically addressed to large tumors that are impossible to be totally sampled, and represent an opportunity to improve ITH detection without extra costs.