Bold statement: Neoadjuvant SAbR prior to surgery shows real potential to change outcomes for RCC patients with caval tumor thrombus, offering strong efficacy with manageable safety. And this is where the debate begins, because not everyone agrees on how to interpret early phase results. Here’s a clear, expanded rewrite that preserves the original meaning and key details while improving accessibility and engagement.
A phase 2 study presented at the 2025 Society of Urologic Oncology Annual Meeting in Phoenix explored the use of neoadjuvant stereotactic ablative radiotherapy (SAbR) before surgical intervention for patients newly diagnosed with renal cell carcinoma (RCC) who also have caval tumor thrombus. The research team reported encouraging oncologic outcomes and demonstrated that this approach is safe and feasible in a high-risk RCC population.
Lin Lin, MD, the presenting author and a urologic oncology fellow at UT Southwestern Medical Center, explained the rationale behind the study. The central idea was straightforward: by radiating the tumor thrombus before attempting surgery, the treatment could reduce the risk of embolization and subsequent tumor spread or recurrence.
Study details show that 23 patients with newly diagnosed RCC were enrolled. Participants received neoadjuvant SAbR either as 40 Gy delivered in five fractions or 36 Gy delivered in three fractions, followed by surgical resection. The median follow-up period was 35.2 months.
Key outcomes included a 12-month relapse-free survival (RFS) rate of 71.4% (80% confidence interval: 56.6 to 82.0; P = .087). This performance favored historical controls treated with surgery alone, which reported a 12-month RFS of 55.7%. Additionally, 12-month overall survival and cancer-specific survival both stood at 95.2%.
From a safety perspective, neoadjuvant SAbR appeared well tolerated. There were no radiation-related adverse events of grade 4 or higher, and no pulmonary embolism events were reported. Perioperative adverse events of grade 3 or higher occurred in 36.4% of patients.
Reference
1. Lin L. Late Breaking Abstract: Phase II trial of neoadjuvant stereotactic ablative radiotherapy for caval tumor thrombus in newly diagnosed renal cell carcinoma. Presented at: Society of Urologic Oncology Annual Meeting; December 2-5, 2025; Phoenix, Arizona.
If this approach proves durable in larger trials, it could redefine the treatment sequence for RCC with caval thrombus. Do you think neoadjuvant radiotherapy should become a standard consideration in such cases, or is more evidence needed to confirm its long-term benefits and safety? Share your views in the comments.
