Harras Zaid, MD, on optimal management of renal cell carcinoma with tumor thrombus

In a recent interview with Urology Times®, Harras Zaid, MD, discusses the complex decision-making involved in managing renal tumors with associated tumor thrombus. He emphasized that the primary challenge for surgeons is determining the optimal treatment approach for these patients.

Zaid is a urologic oncologist at the University of Texas at Austin Dell Medical School and Ascension Health Group.

While Zaid noted that surgical resection remains the standard of care when feasible, patient-specific factors such as tumor anatomy, comorbidities, and overall performance status often complicate this decision. In select cases, these limitations prompt consideration of multimodal strategies prior to surgery.

For patients who are not surgical candidates, Zaid stresses the importance of obtaining a biopsy to establish histologic subtype, followed by multidisciplinary discussion to evaluate upfront systemic therapy, radiation, or a combination of both. He notes that there is a lack of level 1 evidence guiding the choice between these strategies. While individual cases may demonstrate dramatic responses—such as a patient he presented who experienced significant tumor regression after combination checkpoint inhibition—these outcomes are not common or predictable.

Zaid also pointed to retrospective data presented at the 2025 Society of Urology Oncology Annual Meeting in Phoenix, Arizona, suggesting that approximately 30% to 40% of patients may experience some regression of tumor thrombus with systemic therapy,¹ which could potentially make surgery more feasible later on. However, there is no clear consensus on optimal patient selection or choice of systemic agents.

Similarly, small series indicate that stereotactic body radiation therapy (SBRT) may induce thrombus regression in some patients, though its role in enabling subsequent surgery remains unclear. Nonetheless, Zaid emphasizes that for patients who are not surgical candidates, systemic therapy and radiation-based approaches should remain accessible options considered on a case-by-case basis.

REFERENCE

1. Choudry M, Briggs L, Jeffery J, et al. Impact of Neoadjuvant Systemic Therapy on Tumor and Tumor Thrombus Regression in Renal Cell Carcinoma with Venous Involvement: A Retrospective Analysis. Presented at: Society of Urologic Oncology Annual Meeting; December 2-5, 2025; Phoenix, Arizona. Abstract 27. https://suo-abstracts.secure-platform.com/a/gallery/rounds/24/details/4994