Asymptomatic Brain Tumors Found in Some Patients with Kidney Cancer

New research from the Memorial Sloan Kettering Cancer Center and the Gustave Roussy Institute found that some patients with metastatic kidney cancer develop asymptomatic brain metastases, which were associated with poorer outcomes.

These new findings, which were published in the Journal of the National Comprehensive Cancer Network, suggest that brain imaging should be considered for this patient population.

“Brain imaging is routinely obtained for kidney cancer patients with symptoms that suggest central nervous system metastases, but none of the patients with brain metastases included here were symptomatic,” added senior author Martin H. Voss, MD, in a press release. “In current practice chest, abdomen, and pelvis are routinely imaged from the time that metastatic disease is first detected yet many oncologists do not image the brain.”

For this retrospective study, Dr. Voss and colleagues evaluated 1,689 patients metastatic renal cell carcinoma (RCC) who were considered for clinical trials between 2001 and 2019 and had undergone baseline brain imaging. Of this cohort, 72 patients, or 4.3% (95% confidence interval [CI], 3.3–5.3) had incidental brain metastases without neurologic symptoms. Metastatic disease in two or more additional organs was found in 86% of patients with these asymptomatic brain metastases.

At data cutoff, 62 of 72 patients with brain metastases (86%) had died. Median follow-up for the remaining 10 patients was 14.1 months, median overall survival was 10.3 months, and the one-year overall survival rate was 48% (95% CI, 37-62).

“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 RCC. 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,” said Eric Jonasch, MD, vice-chair of the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology Panel for Kidney Cancer. “Second, they underscore the utility for MRI imaging of all patients with metastatic RCC both at initial diagnosis, and at regular intervals, to detect occult brain metastases, since specific treatment strategies are required for this patient population.”