Rondón, Gabriela

Abstract Background: Pulmonary function tests, forced expiratory volume in 1 s (FEV₁) and diffusing capacity for carbon monoxide (DLCO), are integral to pre-transplant evaluation of allogeneic hematopoietic cell transplantation (HCT) candidates because they estimate the risk of early post-HCT death and respiratory failure. Interpretation has historically relied on race-specific Global Lung Function Initiative equations from 2012 (GLI-2012). In 2021 the Initiative released race-neutral equations (GLI-Global). The influence of adopting GLI-Global on risk stratification, outcome prediction, and transplant eligibility is unknown. Methods: We retrospectively analyzed 8808 adults who underwent first allogeneic HCT at four United States centers between 1999 and 2021. FEV₁ values were converted to z-scores with both GLI-2012 and GLI-Global, whereas DLCO z-scores were calculated with GLI-2017 which is a race neutral equation. Pulmonary impairment was graded with the Lung Function Score (LFS); each component [FEV₁ and DLCO] receives 1 to 6 points based on percent predicted (> 80 % = 1, 70-79 % = 2, 60-69 % = 3, 50-59 % = 4, 40-49 % = 5, < 40 % = 6) and the sum of 2 to 12 maps to grades I (2), II (3-5), III (6-9), and IV (10-12). Primary endpoints were non-relapse mortality (NRM) at 120 days and 2 years, intensive care unit admission, and invasive mechanical ventilation. Prediction was assessed with Cox proportional hazards models and Harrell c-statistics. Results: Switching to GLI-Global reclassified 4.2 % of patients (368 of 8808) across LFS strata. Reclassification was racially asymmetric: 12.2 % of Black patients moved to higher-risk grades whereas 3.9 % of White patients moved to lower-risk grades. C-statistics for FEV₁ z-scores were nearly identical with GLI-Global versus GLI-2012: 2-year NRM 0.544 vs 0.542, 120-day NRM 0.566 vs 0.568, intensive care admission 0.545 vs 0.538, and mechanical ventilation 0.605 vs 0.605; confidence intervals overlapped for every comparison. Continuous z-score models consistently outperformed categorical cut-offs for each outcome: 2-year NRM 0.544 vs 0.518, 120-day NRM 0.566 vs 0.523, intensive care admission 0.545 vs 0.515, and mechanical ventilation 0.605 vs 0.529; confidence intervals did not overlap for every comparison. The composite LFS outperformed models that used FEV₁ or DLCO alone. Extrapolating cohort reclassification rates to 38,606 adults aged 40 to 84 who received allogeneic HCTs reported to the Center for International Blood and Marrow Transplant Research between 2009 and 2018 predicts that 1521 patients, including 509 Black adults, would shift LFS grades and could face altered transplant eligibility. Conclusions: Race-neutral GLI-Global equations modestly change pulmonary risk categorization, disproportionately raising scores for Black HCT candidates, yet maintain predictive accuracy for early mortality, respiratory failure, and intensive care use. Continuous dual-variable models and the composite LFS provide superior prediction. Although race-neutral interpretation aligns with current society guidelines, its tendency to classify Black individuals as higher risk highlights the need for refined continuous models that limit unnecessary reclassification and increased disparities in transplant eligibility.

Abstract Rationale: Hematopoietic cell transplantation (HCT) risk scores have seen minimal updates over the past 20 years, despite advancements in clinical practice. Pulmonary function test (PFT) thresholds, initially based on NHANES reference equations, now have alternative reference standards from the Global Lung Function Initiative (GLI) 2012 and GLI-Global, which may reclassify patients and affect outcomes. This study investigates the impact of GLI reclassification on outcomes in HCT, comparing traditional fixed thresholds with continuous (z-score) risk assessment models. Methods: A retrospective review of 3,120 adult patients who underwent autologous HCT at MD Anderson Cancer Center from 1999 to 2015 was conducted. Primary endpoints were ICU admission, mechanical ventilation (IMV), and survival within 120 days post-transplant. PFT measures (FEV1, FVC, DLCO) were calculated using GLI-2012 and GLI-Global reference equations, analyzed both continuously (z-scores) and categorically by ATS/ERS guidelines. Cox proportional hazards and logistic regression models were employed, with AUROC comparisons to evaluate predictive performance. Results: The cohort had a mean age of 49 years (SD 14), with 41% female and 77% White. Of the 3,120 patients included in the study, the cohort consisted of 77% White, 5.4% Black, 3.3% Asian, and 14% identifying as other ethnicities. At 120 days, mortality was 1% (n=41), ICU admission 5% (n=169), and IMV 2% (n=70). Continuous DLCO was associated with a lower risk of mortality (HR: 0.75; p=0.03), ICU admission (OR: 0.83; p=0.01), and IMV (OR: 0.80; p=0.02). GLI-Global's FEV1 z-scores were also significant for mortality (HR: 0.70; p=0.01), ICU admission (OR: 0.74; p<0.0001), and IMV (OR: 0.70; p=0.0003). Categorical analyses showed significant mortality reduction with normal DLCO (HR: 0.46; p=0.01) and ICU admission reduction with normal FEV1 GLI-2012 (OR: 0.63; p=0.02). Reclassification by race, as shown in Figure 1, indicated that race-specific equations overestimated PFT values in Black patients and underestimated them in Asian patients. Conclusion: Reclassification by GLI reference equations, particularly using continuous z-scores, significantly influences post-HCT outcomes, suggesting that continuous assessment may improve risk stratification. Including race does not improve the model's performance. These findings support integrating updated PFT references and continuous risk models into HCT prognostic tools for enhanced clinical decision-making.

Background: Ph-like ALL is a high-risk subset of B-lineage ALL that responds poorly to standard chemotherapy regimens. While allogeneic hematopoietic cell transplantation (HCT) is routinely recommended for patients with Ph-like ALL, large multicenter data addressing its role is limited. Here, we conducted a multicenter study to evaluate the role of HCT in adolescent and young adult (AYA) and adult patients (pts) with Ph-like ALL and compare their outcomes to pts with Ph-pos and Ph-neg (non-Ph-like) ALL. Methods: The study included pts (age ≥18) with B-lineage ALL who received HCT in first complete remission (CR1) at 3 academic centers (MD Anderson Cancer Center, City of Hope and Mayo Clinic) between 2006 and 2021. Pts were divided into 3 main subgroups: Ph-like, Ph-pos and Ph-neg ALL. Ph-like ALL cases were identified using cumulative data obtained by targeted RNA sequencing, conventional cytogenetics, FISH studies, whole genome chromosomal microarray and flow cytometry. Measurable residual disease (MRD) prior to HCT was measured using flow cytometry with a sensitivity of 0.01% for Ph-neg and Ph-like ALL, and with a PCR assay for BCR::ABL1 for Ph-pos ALL. MRD-negativity was defined as <0.01%. Predictors of relapse were evaluated in univariate and multivariate analysis using Fine-Gray sub-distribution hazard models considering non-relapse mortality (NRM) as a competing risk. Results: 673 patients were identified, 83 (12.3%) had Ph-like ALL, of which 73% had CRLF2-alterations. The remaining patients were classified either as Ph-pos (N=271, 40.3%) or Ph-neg ALL (N=319, 47.4%). Patients with Ph-like ALL were younger (median age 40 years vs 48 and 46 years for Ph-pos and Ph-neg ALL, respectively, p=0.01), more likely to be of Hispanic ethnicity (69% vs 32% and 48% for Ph-pos and Ph-neg ALL respectively, p<0.001). Patients with Ph-like ALL were also more likely to have induction failure (24% vs 2% and 11% for Ph-pos and Ph-neg ALL, respectively, p=0.001). A summary of pts characteristics for each subgroup can be found in Table 1. The median follow-up was 30, 52 and 48 months for patients with Ph-like, Ph-pos and Ph-neg ALL, respectively. In univariate analysis, 3-yr OS and PFS did not differ significantly (66% and 59% vs 59% and 54%, p=0.1) between patients with Ph-like and Ph-neg ALL, respectively. Similarly, the cumulative incidence of relapse was comparable between patients with Ph-like and Ph-neg ALL (22% vs 20%, respectively, p=0.7). In contrast, the 3-yr OS (75%, p<0.001) and PFS (70%, p=0.001) were significantly higher and relapse rate significantly lower (12%, p=0.003) in pts with Ph-pos ALL compared with Ph-like or Ph-neg ALL (Figure 1). The inferior survival in patients with Ph-like and Ph-neg ALL was likely attributable to higher relapse rates (22% and 20% vs 12%, respectively, p=0.003) compared to Ph-pos ALL. Finally, the 3-yr NRM rate in patients with Ph-like ALL was comparable (20% vs 18% and 23%, respectively, p>0.1) to Ph-pos and Ph-neg ALL. We confirmed that the relapse rate in patients with Ph-like ALL was comparable to the rate in pts with Ph-neg ALL (HR=1.02, 95% CI 0.6-1.8, p=0.9) on multivariate analysis (MVA). Ph-pos ALL was associated with a significantly lower relapse rate compared with Ph-neg ALL (HR=0.4, 95% CI 0.3-0.7, p<0.001). MRD positivity prior to allo-HCT was the only additional significant predictor for relapse on MVA (HR=2.9, 95% CI 1.8-4.7, p<0.001). Conclusions: HCT appears to overcome the poor prognosis of patients with Ph-like ALL. Despite higher induction failure rates, patients with Ph-like ALL undergoing HCT in CR1 had similar outcomes to other Ph-neg ALL subsets. The impact of effective salvage therapy leading to MRD-negativity in CR1 in this group is under investigation and will be reported. Further studies are needed to assess the impact of different Ph-like alterations on HCT outcomes. Outcomes for patients with Ph-pos ALL are significantly better than other groups, likely due to the use of TKIs pre- and post-HCT.