Page 262 - Haematologica Vol. 107 - September 2022

LETTER TO THE EDITOR
Autologous stem cell transplantation in an older adult population
Over the past decade there has been a remarkable prog- ress in the treatment of multiple myeloma (MM) and non- Hodgkin lymphoma (NHL). Nevertheless, autologous stem cell transplant (ASCT) remains an integral part of the care for patients with MM, and one of few curative options for patients with relapsed/refractory (R/R) NHL. Historically, an arbitrary age of 65 has been used to determine pa- tient’s eligibility for ASCT. This stems from the fact that the majority of prospective studies evaluating efficacy of ASCT in MM have excluded patients >65 years old.1 Cur- rently, nearly half of new diagnoses of MM and NHL are >75 years old.2,3 However, the data on safety and efficacy of ASCT patients >75 years remains limited.
Racial minorities remain severely underrepresented in cancer clinical trials, thus limiting the generalizability of clinical cancer research to these populations.4 Data on ASCT in elderly minority patients has to our knowledge not yet been reported. In this letter we present results of a retrospective study showing comparable transplant re- lated mortality in minority patients >75 years old as com- pared to those aged 55-66 years old.
We conducted a retrospective cohort study comparing ASCT outcomes in patients >75 years old and 55-65 years old for the diagnosis of MM or NHL, who were conditioned with either melphalan or BEAM (carmustine, etoposide, cytarabine, melphalan) respectively. Patients were se- lected from an internal database which has all ASCT per- formed at our center between 2005-2021. The study group included patients >75 years old. The control group in- cluded patients 55-65 years old that were matched to the study group patients by sex and date of transplant. Elec- tronic medical records were reviewed to gather data. The primary outcomes were admission mortality, length of stay, time to white blood cell (WBC) and platelet engraft- ment, incidence of neutropenic fever, positive blood cul- ture, intensive care unit (ICU) admission, and 30-day rehospitalization rate. Secondary outcome were 1- and 5- year mortality rates. Patients with no follow-up post ASCT and ASCT prior to 1- and 5-year follow-up were excluded from analysis. Admission mortality and long-term survival probability were calculated using log rank test. Continu- ous data was reported as medians and interquartile ratios (IQR) and analyzed using Wilcoxon rank sum test. Signifi- cance was denoted by a=0.05.
Between 12/2005 and 3/2021, there were 43 patients >75 years old who underwent ASCT for MM or NHL. Data col- lection was censored on 4/2/22. Table 1 summarizes pa- tient characteristics at index ASCT. Twenty-four (55.8%)
patients were female. The median age in the study group was 77.1 (range, 76.2-77.9) years old and 61.9 (range, 57.4,- 63.0) years old in the control group. Both groups predomi- nantly included minority patients: 55.8% and 46.5% were Spanish/Hispanic/Latino and 25.6% and 14.0% were Afri-
Table 1. Patient characteristics.
Study
Control
N
Female, N (%)
43
24 (55.8)
43
24 (55.8)
Age, median (IQR)
77.1 (76.2-77.9)
61.9 (57.4-63.0)
Performance status, N 100
90 80 70 60
28 5 14 5 3 1
31 2 16 7 3 3
Minority, N (%) Spanish/Hispanic/Latino African American
Non-minority*, N (%)
24 (55.8) 11 (25.6) 8 (18.6)
20 (46.5) 6 (14.0) 17 (39.5)
Medicaid insurance**, N (%) Minority
Non-minority
12/33 (36.4) 0
20/25 (80.0) 9/13 (69.2)
Auto-HSCT indication Multiple myeloma, N (%)
Upfront Relapsed/refractory
34 (79.1) 28 (82.4) 6 (17.6)
33 (76.7) 24 (72.7) 9 (27.3)
Melphalan dose, N (%) 200 mg/m2
140 mg/m2
100 mg/m2
50 mg/m2
5 (14.7) 19 (55.9) 9 (26.5) 1 (2.9)
28 (84.8) 5 (15.6) 0
0
Lymphoma, N (%) *** DLBCL
Other
Upfront Relapsed/refractory
9 (20.9) 7 (77.8) 2 (22.2) 4 (44.4) 5 (55.6)
10 (23.3) 7 (70.0) 3 (30.0) 6 (60.0) 4 (40.0)
Prior auto-HSCT for relapsed disease, N (%)
1 (2.3)
2 (4.6)
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Auto-HSCT: autologous hematopoietic stem cell transplant; IQR: in- terquartile ratio; DLBCL: diffuse large B-cell lymphoma. *Non-minor- ity patients include those with ethnicity other than Spanish/Hispanic/Latino and those without documented Race/Eth- nicity. ** In the study group: 1/43 patient had unknown insurance status, 39/42 had Medicare coverage, of 11/39 had dual Medicare/Medicaid coverage, 1/42 patient only had Medicaid coverage and 2/42 had commercial insurance. In the control group: 5 had un- known insurance status, 24/38 had only Medicaid coverage, 5/38 had dual Medicare/Medicaid coverage, 1/38 had only Medicare, 8/38 had commercial insurance. ***All patients with lymphoma received BEAM (carmustine, etoposide, cytarabine, melphalan) conditioning.