Findings from a study of incidental brain metastases in patients with metastatic renal cell carcinoma (mRCC) suggest that baseline brain imaging should be considered in most patients with metastatic kidney cancer.1,2
The retrospective analysis, which was conducted by researchers at Gustave Roussy and Memorial Sloan Kettering Cancer Center (MSK), found that 4% of patients with mRCC had asymptomatic brain metastases.
"With 4% overall incidence in this cohort, one might conclude that baseline brain imaging should be considered in all patients with metastatic kidney cancer, particularly those with multiorgan involvement and/or pulmonary metastases," lead MSK researcher Ritesh R. Kotecha, MD, stated in a press release.
The retrospective analysis included patients with mRCC evaluated between 2001 and 2019 for clinical trial participation at Gustave Roussy and MSK who had received brain imaging during the evaluation, even though there was not clinical suspicion of brain involvement.
Overall, the analysis included 1689 patients enrolled across 68 trials. At a median follow-up of 14.1 months, 72 (4.3%) patients were identified as harboring occult brain metastases. The risk status was favorable, intermediate, and poor in 26%, 61%, and 13%, of patients, respectively, based on the International Metastatic RCC Database Consortium risk status scale. Further, 2 or more extracranial sites of disease were identified in 86% of patients; this included 92% of patients having lung metastases.
"Brain imaging is routinely obtained for kidney cancer patients with symptoms that suggest CNS metastases, but none of the patients with brain metastases included here were symptomatic," senior researcher Martin H. Voss, MD, also with MSK, stated in the press release. "In current practice, chest, abdomen, and pelvis are routinely imaged from the time that metastatic disease is first detected, yet many [clinicians] do not image the brain."
In 40% of the patients, the largest brain metastasis was more than 1 cm in diameter, and CNS involvement was multifocal in 38.5% of patients. Almost all patients (93%) received localized brain-directed therapy, which mainly consisted of radiotherapy.
The median overall survival (OS) was 10.3 months, with a 1-year OS probability of 48%. The investigators did not observe a correlation between OS and IMDC risk, number of lesions, or size of lesions.
“The retrospective study by Kotecha et al demonstrates that incidental brain metastases occur in a clinically significant percentage of patients with newly diagnosed metastatic renal cell carcinoma," Eric Jonasch, MD, professor, Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, who was not involved in this research, commented in the press release.
"The findings in this study are important for two reasons. First, they show that the overall prognosis of patients with brain metastases is consistently worse than the broader population of patients with metastatic renal cell carcinoma. We need to develop a deeper scientific understanding of why this patient population has a worse outcome, and we need to include them in future clinical trials. Second, they underscore the utility for MRI imaging of all patients with metastatic renal cell carcinoma both at initial diagnosis, and at regular intervals, to detect occult brain metastases, since specific treatment strategies are required for this patient population,” added Jonasch.
1. Kotecha RR, Flippot R, Nortman T, et al. Prognosis of incidental brain metastases in patients with advanced renal cell carcinoma. J Natl Compr Canc Netw. 2021;19(4):432-438. doi: 10.6004/jnccn.2020.7634
2. JNCCN Study: Important Potential Role for Routine Brain Imaging in Advanced Kidney Cancer. Published online April 13, 2021. Accessed April 19, 2021. https://prn.to/3xgXBWL.