Metastatic Renal Cell Carcinoma: Synchronous vs. Metachronous Metastatic Disease and Its Impact on Cancer Control in the IO-Combination Era-Real World Experiences from a Multi-Institutional Cohort

The classification of patients with metastatic renal cell carcinoma (mRCC) has traditionally relied on clinical models like the International Metastatic RCC Database Consortium (IMDC) criteria. These tools, developed in the era of VEGF-directed therapies such as tyrosine kinase inhibitors (TKIs), have guided prognosis and treatment decisions for over a decade. But as the treatment landscape has shifted toward immune checkpoint inhibitors (IO), the relevance of these legacy tools has come under question.

In our recent study (PMID: 40393815), we specifically investigated whether the timing of metastatic occurrence—synchronous versus metachronous disease—remains prognostically meaningful in the IO era. While prior TKI-based studies suggested that patients who develop metastases long after initial diagnosis tend to do better, this had not been robustly tested in the context of IO-based therapy.

To answer this, we conducted a multi-institutional real-world study involving over 350 patients across Germany, all treated with IO in the first-line setting. Importantly, we included diverse IO-based regimens and categorized patients by the interval between diagnosis of the primary tumor and the onset of metastasis.

Our findings show that patients with long metachronous metastases—defined as occurring ≥12 months after initial diagnosis—continue to have superior outcomes, even in the IO era. This suggests that biological features underpinning delayed metastatic spread (perhaps including tumor immunogenicity or host immune dynamics) retain clinical significance despite the shift in therapy.

This study is part of the growing portfolio of GesRU Academics, a collaborative research group comprising 11 academic urology departments across Germany. What makes this initiative unique is that it’s largely driven by trainee physicians—young doctors who balance clinical responsibilities with scientific inquiry and benefit from cross-institutional mentorship and shared data infrastructures.

For us, this project not only helps inform real-world clinical practice but also reflects the power of grassroots academic collaboration in generating clinically relevant evidence. As our field continues to evolve rapidly, we believe it’s critical to reassess legacy prognostic tools and develop new models tailored to the immunotherapy era.

If you’re interested in contributing to this goal by collaborating with GesRU Academics or contributing to future multi-institutional projects in urologic oncology, we would be glad to hear from you (contact: )

Written by: Charis Kalogirou, MD, Department of Urology and Pediatric Urology, Julius-Maximilians University of Würzburg, Germany. On behalf of the GesRU Academics Work Group “Renal Cell Carcinoma”

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