Association of Pre-Transplant Comorbidities with Long-Term Quality of Life (QOL) Among Survivors After Allogeneic Hematopoietic Cell Transplantation (HCT)

Whether pre-transplant comorbidities are associated with QOL after allogeneic HCT is unknown. We used the HCT-comorbidity index (CI) in order to investigate possible associations of baseline comorbidities with different domains of QOL among long-term survivors.

All survivors >17 years of age, who were 3-18 years after HCT for hematological malignancy, without active cancers for 2 years, and with internet access were eligible for the study and hence were approached by mail for participation. Assessment was conducted with an online survey that collected information on socioeconomic status, the Short-Form Health Survey (SF-36), Fatigue Symptom Inventory (FSI), Symptom Check List-90-Revised (SCL-90-R) for depression, Cancer and Treatment Distress (CTXD) scale, ENRICHD Social Support Instrument (ESSI), Social Activity Log (SAL), and self-reported comorbidity index (SR-CI) for general health.

Of 1,775 participants approached for the study, 775 were eligible, consented and completed the assessments, of whom 588 were recipients of allogeneic HCT, of whom 398 were given HLA-matched grafts and contributed to this study. Median age at HCT was 43 (3-76) years and median time from HCT was 7.5 (3.1-17.2) years. Diagnoses were mostly myeloid (83%) or lymphoid (16%) malignancies. Baseline HCT-CI scores were 0 vs. 1-2 vs. ≥3 in 47%, 35%, and 18% of survivors, respectively. High-intensity conditioning regimens were used in 88% of the survivors, and grafts were from related donors in 55% of survivors. Rate of post-HCT relapse was 11%.

Linear and logistic regression models were adjusted for pre-transplant characteristics, socioeconomic factors, and relapse after HCT. When scores of QOL measures were assessed on a continuous scale, HCT-CI scores of 0 vs. 1-2, vs. ≥3 were associated with impaired physical health as evidences by decreasing means (SD) of 48.9 (10.4) vs. 47.2 (11.2) vs. 44.9 (10.4), respectively, of the physical component score of the SF-36 (p= 0.04). Other QOL measures were assessed as dichotomized outcomes based on standard cut-offs of the population norm. Higher HCT-CI scores were significantly associated with increased depression, increased distress from cancer or its treatment, diminished social support, and higher comorbidity burden among long-term survivors (Table). HCT-CI scores were not associated with the mental component of the SF-36, increased fatigue, or social activities.

This is, to the best of our knowledge, the first evidence that pre-transplant comorbidities, captured by a prognostic comorbidity index, were associated with long-term QOL outcomes for survivors after allogeneic HCT. Prospective studies are warranted to explore associations of comorbidities with QOL early after HCT and to evaluate preventive or rehabilitation interventions that might improve long-term QOL for survivors, particularly those with high pretransplant comorbidity burden.