Fatigue, However Measured, Continues to Refine Prognosis in Higher Risk MDS: An MDS-CAN Study

Background:
The incorporation of patient-reported outcomes with traditional disease risk classification, was found to strengthen survival prediction in patients with myelodysplastic syndromes (MDS). A recently reported model, FA-IPSS(h), found that patients’ reported fatigue, assessed by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life-Core 30 (QLQ-C30), among higher-risk IPSS population, further stratifies them into distinct sub-groups with different survival outcomes (Efficace et al, 2018). Compared to the IPSS, the revised IPSS (IPSS-R) is more refined in prognostic assessment and an IPSS-R score of > 3.5 may identify higher risk disease (Pfeilstocker et al, 2016). The Edmonton Symptom Self Assessment Scale (ESAS) Global Fatigue Scale (GFS), is a single-item fatigue rating scale (0-10, with 10 being the highest degree), which has been previously recommended by the National Comprehensive Cancer Network to screen for fatigue in all cancer populations.

Aims:
(1) to validate the FA-IPSS(h), among the Canadian MDS registry (2) investigate whether a modified index, integrating higher risk by IPSS-R with patient reported fatigue according to the GFS, is able to identify individual subgroups with divergent overall survival (OS).

Methods:
All adult patients diagnosed with MDS with an IPSS-R score >3.5 within 6 months before the date of registration were eligible for this analysis. Fatigue was assessed both by the QLQ-C30 questionnaire and the GFS. Frailty was assessed by the Canadian Study of Health and Aging (CSHA) 9 point Rockwood clinical frailty scale. Survival was calculated using standard Kaplan–Meier analysis.

Results:
This analysis included 331 patients. Median age was 73 years (range, 30-98 years), 65.7% were male, median blast % was 6% (range, 0-30), median IPSS-R score was 5.2 (range, 3.5-10) and 55% had high and intermediate-2 (Int-2) IPSS risk, 68% had high and very high IPSS-R risk disease, 66% were exposed to a hypomethylating agent. Median fatigue scores increased with Rockwood frailty scores. The median QLQ-C30 fatigue score was 33 (interquartile range (IQR), 22-55.6) and 4 (IQR, 2-6) by the GFS with 59% recording high fatigue (>4). At a median follow-up of 17 months (IQR, 9-30 months), 233 deaths were observed. The actuarial median OS was 19.3 months (95% CI, 16.5-21.7). We applied the FA-IPSS(h) using QLQ-C30 fatigue cutoffs of 45 (figure 1a) and found a significant difference in OS (p<0.0001) (table 1). We then divided the cohort into 2 groups: A) IPSS-R score >3.5 + Low Fatigue (<45) (n=226) and B) IPSS-R score >3.5 + High Fatigue (≥45) (n=96). We found a significant difference in OS between these 2 groups, median OS 19.5 months (95% CI, 17.2-24.3) in group A versus 15.2 months (95% CI, 11.9-22.0) in group B (p=0.02) (figure 1b). We found similar results with these refinements, using the QLQ-C30 cutoff of 33 (the median in our patient population) (p<0.0001). Similarly, high fatigue defined by ESAS GFS (>4), was able to distinguish OS using the IPSS (p<0.0001) (figure 1c) and IPSS-R >3.5 (p=0.005) (figure 1d).

Conclusions:
We were able to externally validate the FA-IPSS (h) using a threshold QLQ-C30 fatigue score of 45, as originally described and 33 (Canadian median), using both the IPSS and IPSS-R (score >3.5) classifications to define higher risk MDS. The easier to deploy ESAS GFS score of >4 further discriminates survival using the IPSS and IPSS-R. This emphasizes the power of self-reported fatigue at refining OS predictions in higher risk MDS and further bolsters the importance of considering patient related outcomes in global assessments.