The Clinical Frailty Scale as useful tool in patients with brain metastases

The Clinical Frailty Scale (CFS) evaluates patients' level of frailty on a scale from 1 to 9 and is commonly used in geriatric medicine, intensive care and orthopedics. The aim of our study was to reveal whether the CFS allows a reliable prediction of overall survival (OS) in patients after surgical treatment of brain metastases (BM) compared to the Karnofsky Performance Score (KPS).

Patients operated for BM were included. CFS and KPS were retrospectively assessed pre- and postoperatively and at follow-up 3-6 months after resection.

205 patients with a follow-up of 22.8 months (95% CI 18.4-27.1) were evaluated. CFS showed a median of 3 ("managing well"; IqR 2-4) at all 3 assessment-points. Median KPS was 80 preoperatively (IqR 80-90) and 90 postoperatively (IqR 80-100) as well as at follow-up after 3-6 months. CFS correlated with KPS both preoperatively (r = - 0.92; p < 0.001), postoperatively (r = - 0.85; p < 0.001) and at follow-up (r = - 0.93; p < 0.001). The CFS predicted the expected reduction of OS more reliably than the KPS at all 3 assessments. A one-point increase (worsening) of the preoperative CFS translated into a 30% additional hazard to decease (HR 1.30, 95% CI 1.15-1.46; p < 0.001). A one-point increase in postoperative and at follow-up CFS represents a 39% (HR 1.39, 95% CI 1.25-1.54; p < 0.001) and of 42% risk (HR 1.42, 95% CI 1.27-1.59; p < 0.001).

The CFS is a feasible, simple and reliable scoring system in patients undergoing resection of brain metastasis. The CFS 3-6 months after surgery specifies the expected OS more accurately than the KPS.