Determinants of renal cell carcinoma invasion and metastatic competence

Tumour thrombi (TT) are intravascular extensions of renal cell carcinomas (RCC) which often lead to distant metastases. Here the authors examine the determinants of vascular invasion and metastasis in a unique cohort of RCC patients with TT using multi-region genomics and in vivo models. Metastasis is the principal cause of cancer related deaths. Tumor invasion is essential for metastatic spread. However, determinants of invasion are poorly understood. We addressed this knowledge gap by leveraging a unique attribute of kidney cancer. Renal tumors invade into large vessels forming tumor thrombi (TT) that migrate extending sometimes into the heart. Over a decade, we prospectively enrolled 83 ethnically-diverse patients undergoing surgical resection for grossly invasive tumors at UT Southwestern Kidney Cancer Program. In this study, we perform comprehensive histological analyses, integrate multi-region genomic studies, generate in vivo models, and execute functional studies to define tumor invasion and metastatic competence. We find that invasion is not always associated with the most aggressive clone. Driven by immediate early genes, invasion appears to be an opportunistic trait attained by subclones with diverse oncogenomic status in geospatial proximity to vasculature. We show that not all invasive tumors metastasize and identify determinants of metastatic competency. TT associated with metastases are characterized by higher grade, mTOR activation and a particular immune contexture. Moreover, TT grade is a better predictor of metastasis than overall tumor grade, which may have implications for clinical practice.

Automated summary

In this study, the authors explore the determinants of vascular invasion and metastasis in RCC patients with tumor thrombi (TT). They found that tumor thrombi associated with metastases are characterized by higher grade, mTOR activation, and a particular immune contexture. TT grade is a better predictor of metastasis than overall tumor grade.