Assessment of Patients Fitness at Diagnosis in Elderly Acute Myeloid Leukemia

Background:Acute myeloid leukemia (AML) is a disease which predominantly affects patients with a median age at diagnosis over 65 years. The elderly population is highly heterogeneous and assessment strategies are needed to define the frailty profile. To date, evaluation of disease-related and patients specific factors in the context of clinic decision making has been largely subjective. Concerning AML therapy, several studies demonstrated improved survival for older patients receiving intensive induction chemotherapy compared to those receiving supportive care alone. Defining this subset of patients who are eligible or "fit" for intensive chemotherapy involves a great deal of subjectivity. Criteria yet have to be standardized across or within institutions.

Aim:Aim of this study was to investigate the validity of four scores for assessment of patient fitness at diagnosis in parallel to physician evaluation. Further patient outcome according the respective evaluation was compared.

Methods: In a single hematology center a total of 85 clinically and molecularly well characterized consecutive elderly (>60 years) patients with newly diagnosed AML were treated from 2012 to 2015 according to age, performance status and co-morbidities. Therapy response was defined according to ELN criteria. Therapy intensity decision was based on an initial haematologist evaluation followed by discussion of the patient case in an interdisciplinary board. Independently from the medical board, in parallel the local geriatric G8 screening tool, consisting of seven items from the Mini Nutritional Assessment (MNA) questionnaire and age, the HCT-CI comorbidity score as well as the AML scores proposed by the German Acute Myeloid Leukemia Cooperative Group, predicting probability of complete remission (CR) and early death (ED) were performed. Overall survival from diagnosis was compared between groups using the Cox model.

Results:A total of 42 (49,4%) patients were evaluated "fit" by the medical board and treated by intensive chemotherapy ("7+3" regimen), whereas 4 patients (4,7%) underwent semi-intensive with hypomethylating agents and 39 patients (45,8%) received palliative therapy (low dose Cytarabine or Hydroxyurea). Twenty-six patients (30,6%) achieved a complete remission after induction chemotherapy, could follow consolidation chemotherapy and six of them underwent allogeneic hematopoietic stem cell transplantation. Fourty-four (51,8%) were non responders and 15 patients (17,6%) died during the first cycle. Overall, the median survival time was 6,7 months (95% CI 3,7-9,5). Primary physician care evaluation was able to define in a statistically significant manner a "fit" from an "unfit" patient. Median survival time from the "fit" patients was 10 moths (95%CI 5-not reached) compared to the "unfit" evaluated patients with 3,4 months (95%CI 1,4-5), p<0.001 with a HR (95%CI) of 3,18 (1,81 to 5,59). Parallel evaluation of patients unfitness according the proposed cut-point of the G8 (≤14), AML for CR (<40) and AML for ED (≥30) scores discriminated significantly patients survival with HRs equal to 3.03 (p<0,001), 2.11 (p=0,007) and 2.83 (p<0.001), respectively. The agreement between the frailty scores and physician evaluation on the prediction of fitness classification was analyzed by calculating the Cohens' Kappa. In this approach a Kappa level of 1,0 denotes perfect agreement. The agreement of was moderate for HCT-CI score and AML score for CR (0.47 and 0.46, respectively). The agreement was fair for G8 and AML score for ED (0.27 and 0.33, respectively).

Summary/Conclusion: In conclusion, in the present AML cohort the applied frailty scores at diagnosis correlated significantly with the median overall survival. Since no perfect agreement was found respect to physician for fitness classification, frailty scores can help to improve the prognosis prediction. These results may encourage a following multi-centre analysis in order to increase the statistic power of the performed analysis.