Improved Survival Outcomes for Kidney Cancer Patients With Brain Metastases

Abstract

Background: Brain metastases (BM) occur frequently in patients with metastatic kidney cancer and are a significant source of morbidity and mortality. Although historically associated with a poor prognosis, survival outcomes for patients in the modern era are incompletely characterized. In particular, outcomes after adjusting for systemic therapy administration and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk factors are not well-known.

Patients and methods: A retrospective database of patients with metastatic renal cell carcinoma (RCC) treated at University of Texas Southwestern Medical Center between 2006 and 2015 was created. Data relevant to their diagnosis, treatment course, and outcomes were systematically collected. Survival was analyzed by the Kaplan-Meier method. Patients with BM were compared with patients without BM after adjusting for the timing of BM diagnosis, either prior to or during first-line systemic therapy. The impact of stratification according to IMDC risk group was assessed.

Results: A total of 56 (28.4%) of 268 patients with metastatic RCC were diagnosed with BM prior to or during first-line systemic therapy. Median overall survival (OS) for systemic therapy-naive patients with BM compared with matched patients without BM was 19.5 versus 28.7 months (P = .0117). When analyzed according to IMDC risk group, the median OS for patients with BM was similar for favorable- and intermediate-risk patients (not reached vs. not reached; and 29.0 vs. 36.7 months; P = .5254), and inferior for poor-risk patients (3.5 vs. 9.4 months; P = .0462). For patients developing BM while on first-line systemic therapy, survival from the time of progression did not significantly differ by presence or absence of BM (11.8 vs. 17.8 months; P = .6658).

Conclusions: Survival rates for patients with BM are significantly better than historical reports. After adjusting for systemic therapy, the survival rates of patients with BM in favorable- and intermediate-risk groups were remarkably better than expected and not statistically different from patients without BM, though this represents a single institution experience, and numbers are modest.

Keywords: Neurosurgery; Prognosis; Renal cell carcinoma; Stereotactic radiosurgery; Targeted therapy.

Figure 1.

Overall survival of all patients stratified by presence of brain metastasis (BM). A, Survival for patients with BM diagnosed prior to starting systemic therapy compared with survival from metastatic RCC diagnosis in patients who did not develop BM. B, Survival from diagnosis of BM after start of first-line of systemic therapy compared to patients without BM at the time of progression on 1^st line systemic therapy.

Figure 2.

Overall survival from diagnosis of metastatic RCC by presence of brain metastasis in patients without prior systemic therapy (see Fig. 1A) according to IMDC risk group.

Figure 3:

Overall survival from the diagnosis of metastatic RCC in patients diagnosed with BM prior to or during 1^st-line systemic therapy (26.4 months; 95% CI: 14.3–39.6) compared with patents never diagnosed with BM (28.7 months; 95% CI: 22.0–39.7).