The therapeutic benefit of immune checkpoint inhibitor plus immune checkpoint inhibitor (IO–IO) or immune checkpoint inhibitor plus tyrosine kinase inhibitor (IO–TKI) combination therapy for renal cell carcinoma (RCC) with inferior vena cava tumor thrombus (IVCTT) remains unclear. This study aimed to evaluate the efficacy and safety of IO-based combination therapies in this challenging clinical setting.
We retrospectively analyzed 41 patients with advanced RCC and IVCTT who received IO-based combination therapy across multiple centers. Clinical responses of the primary tumor and IVCTT, as well as treatment-related adverse events (TRAEs), were assessed and compared between IO–IO and IO–TKI regimens.
The cohort comprised 26 men and 15 women, with a mean age of 66.2 years (range, 40–86). IVCTT levels were cT3b in 24 cases and cT3c in 17 cases. Fifteen patients received IO–IO therapy and 26 received IO–TKI therapy. The mean maximum reduction in primary tumor diameter was 19.8 mm (22.2%): 21.5 mm (28.8%) with IO–IO and 18.8 mm (20.0%) with IO–TKI. The mean maximum reduction in IVCTT height was 20.6 mm (25.3%): 18.7 mm (11.4%) with IO–IO and 21.7 mm (33.3%) with IO–TKI. Downstaging of IVCTT level occurred in 16 cases (39.0%; IO–IO, 46.7%; IO–TKI, 34.7%), while upstaging occurred in 1 case (2.4%). Tumor shrinkage of both the primary lesion and IVCTT was more frequent in the IO–TKI group (primary tumor, p=0.0325; IVCTT, p=0.0112). Approximately 27% of patients in the IO–IO group experienced increased IVCTT height. No significant differences were observed between groups in overall relative shrinkage, IVCTT downstaging rate, TRAE incidence, surgical outcomes, or prognosis.
IO-based combination therapy demonstrated therapeutic efficacy against both the primary tumor and IVCTT. These findings suggest that IO-based combinations may represent a feasible treatment option, allowing safe cytoreductive nephrectomy following systemic therapy in selected patients with RCC and IVCTT.
None