CT-290: Clinical Frailty Scale as a Novel Tool to Evaluate Patients’ Eligibility for Allogeneic Stem Cell Transplant: A Single-Center Experience on 234 Patients >50 Years Old

Context Clinical frailty scale (CFS) is a scale ranging from 1 (very fit) to 9 (terminally ill) for increasing degrees of frailty extensively used in several geriatric contexts. Currently, no study on CFS is available in an allo-HCT setting. Objective To evaluate the prognostic value of CFS on OS and NRM in allo-HCT. Patients and Methods Overall, 234 consecutive patients aged >50 y were transplanted at our center from 2006 to 2020. Median follow-up: 4.03 y (95%CI: 3.54–5.90). CFS was retrospectively calculated by an external physician blind to transplant outcome. Results Cohort characteristics were the following: median age 59 y (range: 50–73), males 147 (63%), AML (44.4%). DRI was high/very-high in 36.8% of cases. Matched related donor was used in 41.5%, unrelated in 46.2%, alternative in 12.3% of cases. Overall, 170 patients (72.6%) received a reduced-intensity conditioning regimen. For the evaluation of patients’ fitness at transplant, the following scores were applied: Karnofsky performance status (≥90 in 91.5%), HCT-CI (≥3 in 43.2%), FIL score (unfit/frail in 6.8%) and CFS (very fit [score 1] in 6.8%, fit [score 2] in 51.3%; managing well [score 3] in 29.9%, and frail [>3] in 12.0%). An increasing CFS score was associated with a higher proportion of FIL frailty and a lower Karnofsky performance status. No significant differences were observed in terms of comorbidities. At last follow-up, 149 (63.7%) patients had died (NRM 41.6%, relapse 58.4%). CFS was strongly associated with OS (2-y-OS of 85.6%, 63.7%, 25.8%, and 7.1% for patients with score 1, 2, 3, and >3, respectively; p<0.0001) and NRM (2-y-NRM of 0%, 15.4%, 33.7%, and 39.2%; p=0.0003). By multivariate analysis, CFS had independent negative prognostic value on OS (HR: 1.87, 95%CI: 1.58–2.22, p<0.001) and NRM (HR: 1.73, 95%CI: 1.30–2.32, p<0.001). As evaluated by the likelihood ratio test and C-statistics, CFS showed a strong predictive value (65.47 and 30.75; 0.695 [SE 0.019] and 0.708 [SE 0.031], for OS and NRM, respectively). Conclusions CFS appears a simple and highly effective tool for transplant outcome prediction among oncohematological patients aged >50 y. These results might suggest the use of this score for improving patient selection.