A phase II clinical trial analyzed 305 patients with untreated clear-cell renal cell carcinoma (ccRCC) to see how tumor genetics affect metastasis patterns and treatment response. The study classified tumors into five clusters based on gene expression, with clusters 1 and 2 labeled "angiogenic" and clusters 4 and 5 labeled "proliferative."
Angiogenic tumors had a higher rate of pancreatic metastases (21% vs. 6.9%) but a lower number of lymph node metastases (2.5 vs. 4.2). In contrast, proliferative tumors had more lymph node metastases (5.5 vs. 3.5). These differences were statistically significant.
Importantly, patients with pancreatic metastases who received sunitinib had about 7 times higher odds of overall response and longer progression-free survival compared to those without pancreatic metastases. This suggests that pancreatic metastasis location may be a marker for sunitinib sensitivity.
The study was funded by NIH grants and is based on a post-hoc analysis of a phase II trial. The results are associations, not proven cause-and-effect, and need confirmation in larger studies.
