Baseline Radiologic Tumor Burden Is Prognostic for OS in Metastatic ccRCC

Baseline radiologic tumor burden is an effective independent prognostic factor for overall survival (OS) in patients with metastatic clear cell renal cell carcinoma (ccRCC) who have received frontline immune-oncology (IO)–based therapy, according to Rashad Nawfal, MD.

Findings from a study presented at the 2024 Kidney Cancer Research Summit showed that among patients with a confirmed diagnosis of metastatic ccRCC who were treated with a first-line IO-based regimen at Dana-Farber Cancer Institute in Boston, Massachusetts between August 2014 and October 2023 (n = 150), every 1-cm increase in baseline radiologic tumor burden was associated with a 5% increase in the risk of death (HR, 1.05; 95% CI, 1.03-1.08; P < .0001). In a multivariable analysis, the association between baseline radiologic tumor burden and OS remained (adjusted HR, 1.04; 95% CI, 1.00-1.08; P = .03). Furthermore, baseline radiologic tumor burden was not significantly associated with time to treatment failure (TTF; adjusted HR, 0.99; 95% CI, 0.97-1.01; P = .428) or time to next treatment (TTNT; adjusted HR, 1.01; 95% CI, 0.99-1.03; P = .453).

“[Going forward], if we show that [baseline radiologic tumor burden] has a good prognostic role and is easy to calculate, then we could include that in [patients’] initial assessments before starting first-line therapy,” Nawfal said in an interview with OncLive^® during the meeting.

In the interview, Nawfal, a postdoctoral research fellow at Dana-Farber Cancer Institute and Harvard Medical School, discussed the rationale for investigating radiological tumor burden in patients with metastatic ccRCC who had received frontline IO-based treatment, expanded on the study’s findings, and explained how these outcomes may affect future clinical practice.

OncLive: What was the rationale for investigating the association between tumor burden and OS in patients with metastatic ccRCC?

Nawfal: RECIST 1.1 criteria is a method used to calculate tumor burden; however, it doesn’t reflect the whole tumor burden in the body. It’s an easy way to calculate [tumor burden] using up to 5 measurable lesions and a maximum of 2 lesions per organ. Some scarce data from 2012 showed that radiologic tumor burden might be associated with survival in patients treated with VEGF TKIs. However, [there were] no data on [radiologic tumor burden] in [patients who had received] first-line IO, so we sought to evaluate the prognostic role of radiologic tumor burden calculated by RECIST 1.1 criteria on patients with metastatic ccRCC treated with first-line IO-based regimens.

What were the methods of this study?

We retrospectively reviewed charts from 150 patients with metastatic ccRCC treated with first-line IO-based regimens. We calculated data on baseline radiologic tumor burden per RECIST 1.1 criteria and collected data on progression-free survival surrogates, which are TTF, TTNT, and OS. We also conducted a multivariable analysis that included the following factors: [history of] nephrectomy; International Metastatic RCC Database Consortium risk groups; and presence of bone, brain, or liver metastases.

What were the key findings from this study?

Baseline radiologic tumor burden calculated by RECIST 1.1 criteria was an independent prognostic tool for OS. Every [1-cm] increase in baseline radiologic tumor burden was associated with a 5% increase in the risk of OS events, and the log-rank P value was less than .0001. This significance still stood after the multivariable analysis.

What are the next steps for this research?

Baseline radiologic tumor burden is an easy variable to calculate, and we are now aiming to validate these findings in clinical trial cohorts and have multiple radiologists do these readings to calculate inter-operator variability.

References

Nawfal R, Eid M, Semaan K, et al. Radiological tumor burden is an independent risk factor for survival in patients with metastatic clear cell renal cell carcinoma (mccRCC) treated with first line immunotherapy (IO)-based regimens. Presented at: 2024 Kidney Cancer Research Summit; July 11-12, 2024; Boston, MA. Abstract 46.