Study finds clinically significant percentage of patients with metastatic renal cell carcinoma develop asymptomatic brain metastases.
Patients who have metastatic kidney cancer could benefit from undergoing baseline brain imaging, according to a recently published study.
In the Journal of the National Comprehensive Cancer Network (JNCCN), investigators from both Memorial Sloan Kettering (MSK) Cancer Center and Gustave Roussy Institute, a leading academic cancer center in France, showed that incidental brain metastases can occur in a clinically significant percentage of patients who have newly diagnosed metastatic renal cell carcinoma.
Consequently, they said, implementing brain imaging – even in asymptomatic patients – could positively impact overall survival rates.
For their study, they included 1,689 patients with metastatic renal cell carcinoma who had been considered to participate in a clinical trial at either facility between 2001 and 2019. These individuals had no clinical suspicion of brain involvement, but they had undergone brain CT or MRI.
When researchers evaluated the patients' scans, they found 72 patients (4.3 percent of the group) had asymptomatic brain metastases. Of that group, 22 were diagnosed via screening for first-line studies, and 50 via screening in the treatment-refractory setting. For those patients, the median 1-year overall survival rate was 48 percent, and the median overall survival was 10.3 months.
Brain imaging is routinely implemented for kidney cancer patients who show evidence of central nervous system involvement, but that is not the case for patients who are symptomatic, they said. Given these results, it could be useful to conduct brain imaging in this patient population.
“With 4 percent 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 multi-organ involvement and/or pulmonary metastases,” said lead MSK researcher Ritesh R. Kotecha, M.D.
The team also identified other areas of cancer spread in patients who had brain involvement. At initial kidney cancer diagnosis, 43 patients (60 percent) had metastatic disease, but by the time of brain metastasis diagnosis, 62 patients (86 percent) had metastatic disease in two or more additional organ systems. The most common was lung (66 patients, 92 percent), followed by liver and bone (18 patients each, 25 percent).
“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,” said senior researcher Martin H. Voss, M.D., medical oncologist with MSK.
According to Eric Jonasch, M.D., professor of genitourinary medical oncology at The University of Texas MD Anderson Cancer Center, the findings of this study are important for two main 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,” said Jonasch, who is the vice chair of the NCCN Clinical Practice Guidelines in Oncology Panel for Kidney Cancer. “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.”
The team did note that their study did not elucidate how frequently brain imaging in these patients should be repeated, pointing to the need for further study.
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