Quality of Life and Comorbidities of Adult Survivors of Allogeneic Hematopoietic Cell Transplant Versus Their Siblings

Background:

Survivors of allogeneic hematopoietic cell transplant (allo-HCT) are at risk of developing chronic health conditions. Prior studies have shown that survivors of allo-HCT in childhood/young adulthood who mainly received high dose total body irradiation (TBI)-based conditioning experience excess health conditions and more distress vs. their siblings. In recent years, allo-HCT is offered to adults of increasing age and there has been increasing use of chemotherapy +/- low dose TBI conditioning rather than high dose TBI. We set out to describe and compare the QoL and comorbidities of adults who underwent allo-HCT with chemotherapy +/- low dose TBI conditioning vs. their siblings.

Methods:

Allo-HCT recipients attending 1 of 2 survivorship clinics at ≥2 years post-HCT without active cGVHD or relapse, were enrolled. Beginning in 2023, participants were asked to forward an electronic version of the study survey to their biological sibling(s). The survey includes the PROMIS-Global Health instrument: raw scores are converted to a mental (MH) and physical health (PH) subscale T-score (population mean 50/SD 10). Comorbidities were scored with a published post allo-HCT morbidity index. Associations between MH and PH-related QoL, comorbidities, and patient/transplant-related variables were investigated with linear regression. Patient and sibling comparisons were made with paired sample and chi-square tests. A significance level of <0.05 was statistically significant & a difference in QoL T-score of 5 was clinically significant.

Results:

Of 330 patients approached during their clinic visit, 320 consented to participate (97%). To date, 105 siblings of 57 recipients have been sent surveys and 47 siblings (45%) of 32 recipients (56%) have completed the survey.

Among all recipients, median age at HCT is 47 (IQR 35-57) with 21% ≥60 years old, 48% are female, 78% are Caucasian, 69% are college educated or more & 51% are working full/part-time. Median time post-HCT is 9 years (IQR 6-14). The mean PH T-score is 48.5 (SD 8.6). In the multivariable model, total number of comorbidities (p<0.01) and a work status of disability (p<0.01) are associated with inferior PH QoL. The mean MH T-score was 49.1 (SD 8.4). In the multivariable model, total number of comorbidities (p<0.01) and a work status of disability (p<0.01) are associated with inferior MH QoL. HCT characteristics, including history of moderate-severe cGVHD, and demographic characteristics are not associated with either QoL subscale.

Among all recipients, the median number of comorbidities is 3 (IQR 1.5-4). The most common comorbidities include hyperlipidemia (39%), hypertension (25%) & hypothyroidism (24%). At least one severe comorbidity (vascular disease, chronic heart/lung/liver/kidney disease or subsequent malignancy) is present in 23% of patients. In multivariable analysis, a greater number of years post-HCT is associated with a greater number of comorbidities (p=0.03) and full/part-time work status is associated with fewer comorbidities (p=0.01).

In the sibling-recipient comparison, median age of siblings and recipients is 55 (IQR 37-66) & 54 (IQR 40-64), respectively. The MH QoL of recipients is statistically, but not clinically, better than their siblings: T-score 52.9 (SD 7.1) versus 49.9 (SD 6.9), respectively, p=0.04. The PH QoL of recipients was not significantly different than their siblings: T-score 52.6 (SD 5.6) versus 50.7 (SD 8.2), respectively, p=0.23. Recipients are suffering from significantly more comorbidities vs. their siblings: median 2.5 (IQR 1.8-4) versus 1 (IQR 0-3), respectively, p=0.03. The prevalence of ≥1 severe comorbidity is greater in recipients vs. siblings, but not statistically significant (13% vs. 2%, p=0.06).

Conclusion:

Adult recipients of allo-HCT, living without cGVHD or relapse and conditioned without high dose TBI, in aggregate experience similar QoL but suffer excess chronic health conditions as compared to their siblings. One in 4 recipients are suffering from ≥1 severe chronic health condition(s). Time post-HCT is associated with comorbidities, suggesting that recipients continue to accumulate health conditions in the years post-HCT. Number of comorbidities, rather than transplant and demographic factors (including prior cGVHD), is associated with impaired MH and PH QoL. Preventative care after allo-HCT is critical, even in those receiving HCT in adulthood without high dose TBI.