PracticeUpdate: Conference Series - EHA 2018

EUTOS Long-TermSurvival Score Superior for Prognosis of Survival in CML Sokal score allocatedmore patients to high-risk group than the ELTS T he EUTOS long-term survival score (ELTS) is recommended to predict long-term survival in patients with chronic-phase (CP) chronic myeloid leukaemia (CML). The 5,154 patients in the combined reg- istry had a median observation time of 5.3 years. Six-year OS probability was 90% (95% CI 89–91%). Of 429 deceased patients, in 175 CML progression prior to death was confirmed (40%). The 6-year CIP of dying of CML was 4% (95% CI 4–5%).

The ELTS was originally developed to distinguish three groups of patients with different probabilities of dying from CML in a cohort of 2,205 imatinib-treated patients who were part of the European Treatment and Outcome Study (EUTOS) registry. The registry contains data on adult patients with CP CML. Many investigators, however, continue to rely on the Sokal score for the prognostic discrimination of CML patients treated with tyrosine kinase inhibitors (TKIs). Of the original cohort, the Sokal score had allocated 23% of patients to the high-risk group, the ELTS score only 12%. In their abstract, the research team, led by Markus Pfirrmann, MsC, a senior scientist, biometrician, and epi- demiologist with the Ludwig Maximilian University of Munich, Germany, stated that the long-term outcome of TKIs suggests that allocating > 20% CP CML patients into a high-risk group is “too pessimistic.” Due to the success of TKIs, the number of deaths from CML has declined considerably. The current study compared risk group allocations and prognoses between the two scoring systems. The researchers found that the Sokal score allocated 13% (n=671) more patients to the high- risk group than the ELTS score. As these patients had significantly and clinically relevant lower cumulative incidence probabilities (CIPs) of death and higher overall survival (OS) probabilities, the allocation of the Sokal score was not appropriate, they concluded. For this study, an additional 2,949 patients from other registry sections were included in the review, and survival was calculated from the date of start of treatment to death. The CIPs of dying of CML were compared with the Gray test and OS probabilities with the log-rank test. Only death after confirmed disease progression was regarded as death due to CML.

From low- to high-risk groups, the Sokal score resulted in 6-year CIPs of 3% (n=1,982 [38% of 5,154], CI 2–3%), 4% (n=1,975 [38%], CI 3–5%), and 8% (n=1,197 [23%], CI 6–10%). This compared to the ELTS score in 6-year CIPs of 2% (n=3,037 [59%], CI 2–3%), 5% (n=1,449 [28%], CI 4–7%), and 12% (n=668 [13%], CI 9–1 5%). Of the 1,197 patients allocated as high risk by the Sokal score, the ELTS score classified 671 (56%) as non-high risk. Compared to the 526 high-risk patients according to both scores (6-year CIP of dying: 12%, CI 9–16%), the CIPs of dying were lower for the non-high risk patients (P = .0003, 6-year CIP: 5%, CI 3–7%). The Sokal high but ELTS non-high-risk patients (6-year OS: 88%. CI 85–91%) showed higher OS than the 526 com- mon high-risk patients (P = .0036, 6-year OS: 81%, CI 76–85%). Of the 3,037 patients identified as low risk by the ELTS score, the Sokal score allocated 1,200 (40%) to non-low-risk groups. The researchers found that without significant CIP differences to the latter group, at 6 years, the CIP of dying was 2% (CI 1–3%) in the 1,837 low-risk and 2% in the 1,200 non-low-risk patients (CI 2–4%). OS of the Sokal non-low-risk patients (6-year OS: 92%. CI 90–94%) was lower than in the cases classified as low-risk by both scores (6-year OS: 95%. CI 94–96%, P = .0186). Overall survival probabilities but not the CIPs of 1,200 patients assessed as low-risk by the ELTS and non-low-risk by the Sokal score were different from the probabilities of 1,837 assessed as low-risk patients by both scores, the researchers stated. For the prediction of long-term survival, they recommended the use of the ELTS score.

respondents (59.9% vs 48.7%, P = .0018). Among all MPN types, those with a BMI score > 25 showed a significantly higher symptom burden than those with a BMI < 25, the researchers found. This asso- ciation was found among patients with both PV and MF subtypes, but not for patients with ET. However, weak but still significant positive correlations were observed between symptom burden and BMI among all MPN subtypes (r=0.14; P < .001). “When looking within disease sub- types, this correlation was higher for PV patients (r=0.18; P < .001) than for ET (r=0.11; P < .001) or MF patients (r=0.11; P < .001),” the investigators stated. The research team concluded that over- weight or obese BMI is associated with a significantly worsened disease-related symptom burden for most MPN subtypes. This relationship was less clear for ET, where weak but significant correlations were observed between BMI as a contin- uous measure and symptom burden, but not when BMI was evaluated as dichoto- mous variable. One limitation to the data, the researchers pointed out, is that weight and height were self-reported and could not be externally validated. “However,” they noted, “these data suggest that interventions to reduce weight in MPN patients may be a strategy to combine with traditional therapy to improve symptomatology.”

www.practiceupdate.com/c/69757

www.practiceupdate.com/c/69936

EHA 2018 • PRACTICEUPDATE CONFERENCE SERIES 11