Decisional Regret Among Older Adults with Multiple Myeloma Undergoing Autologous Hematopoietic Stem Cell Transplantation

Introduction Autologous hematopoietic stem cell transplantation (ASCT) is an important treatment modality for all patients with multiple myeloma (MM). In the US, over half of the patients undergoing ASCT are over 60 years (y) of age. Prior studies have shown that up to 15% of allogenic stem cell transplant recipients experience decisional regret. The prevalence of decisional regret among older adults undergoing ASCT is unknown. Methods We included adults ≥ 60 y (at the time of transplant) with MM who underwent ASCT and received either full-dose melphalan (200 mg/m2) or reduced-dose melphalan (140 mg/m2) at a single institution from 02/2021 to 08/2022. At baseline, all patients underwent a comprehensive geriatric assessment. At 3 months post-ASCT, participants completed a 5-item decision regret scale (DRS) (Brehaut JC et al MDM 2003). Each item was coded on a 5-point Likert scale, and a total DRS score (range 0-100) was calculated with 0 representing minimal/no regret and 100 representing high regret. We studied response patterns for each item in all patients and a subgroup of those with age ≥ 70y. Subsequently, we used a semiparametric proportional odds model to study the association between age, sex, race/ethnicity, melphalan dose and a deficit accumulation frailty index (FI) (Giri S et al JAGS 2021), and decisional regret. All hypothesis testing was two sided and the level of significance was chosen as 0.05. Results A total of 54 patients were included with a median age of 67 y at ASCT (Interquartile Range, IQR: 64 - 71 y; 38% (20) with age ≥70 y) with 65% men, 65% non-Hispanic white, 15% frail (FI > 0.35) and 41% received dose-reduced melphalan. The overall median DRS score was 10 (IQR: 0-25) with 28 % having a score of 0. Decision to undergo ASCT: 98% of the patients agreed/strongly agreed with “It was the right decision” while 83% agreed/strongly agreed with “I would make the same decision again”. Regret my decision: 6% of patients agreed/strongly agreed to “I regret my decision”. Decision caused me a lot of harm: 19% agreed/strongly agreed to “The decision caused me a lot of harm”. Wise decision: 96% of patients agreed/strongly agreed to “It was a wise decision”. Similar results were seen among adults ≥ 70y, where 100% of patients agreed/strongly agreed to “It was a wise decision”, 95% agreed/strongly agreed to “It was the right decision”, 80% agreed/strongly agreed to “I would make the same decision again”. Meanwhile, 10% agreed/strongly agreed to “I regret my decision” while 20% agreed/strongly agreed with “The decision caused me a lot of harm”. The median DRS score in this cohort was 5 (IQR: 0-25) with around 40 % having a score of 0. In the multivariable model, neither age (OR, 1.075 per year increase; 95% CI, 0.935 - 1.234), female sex (OR, 1.075; 95% CI, 0.387 - 3.004), non-white race (OR, 0.597; 95% CI, 0.218 - 1.633), FI (OR, 1.282 per 0.1 increase; 95% CI, 0.891 - 1.845) nor full-dose melphalan (OR, 2.596; 95% CI, 0.673 - 10.022) were associated with higher odds of having decisional regret. Conclusion Our study found a very low prevalence of decisional regret among older adults with MM who have undergone ASCT. Further, there was no association between age and decisional regret. Taken together, our study supports existing literature that chronologic age should not be a sole determinant of transplant eligibility and carefully selected older adults can have a favorable experience and low decisional regret following ASCT.