Patient eligibility for HCT

Identifying and evaluating patients who may benefit from hematopoietic cell transplantation (HCT) involves many factors, including overall health, prior therapies, age, disease and disease stage. If an allogeneic transplant is being considered, it is important to identify available unrelated donors, related donors or cord blood units as soon as possible.

Patients under consideration for HCT require a thorough evaluation performed by a transplant physician. A comprehensive pre-transplant evaluation should:

• Determine the patient’s health and performance status
• Assess the patient’s disease status
• Guide the informed consent process
• Identify any psychosocial issues that would interfere with the transplant procedure/recovery [1]

Well-established health and performance status criteria to assess patient eligibility for HCT include:

• Age
• Karnofsky performance score
• Left ventricular ejection fraction
• Pulmonary function test; forced vital capacity
• Diffusion capacity (DLCO)
• Kidney function
• Liver function
• Mental health [2,3]

Recent research has shown that age alone should not be a determinant for HCT eligibility. [4,5] Transplant physicians therefore generally do not set an upper age limit for transplant and instead assess HCT eligibility on other clinical factors such as presence of co-morbidities and geriatric/frailty assessments. [4,6]

For more than a decade, transplant physicians have been using the HCT comorbidity index (HCT-CI) to evaluate HCT candidates. The HCT-CI measures the prevalence and severity of comorbidities in 17 organs. It is useful in assessing the suitability of HCT for patients, and it can also provide valuable prognostic information after HCT. [7,8]

Assessing patient eligibility using an HCT-specific tool is important because research has shown that physical function and co-morbidities, and not chronological age alone, should be considered when determining eligibility for transplant. [9] Therefore, many older patients—once considered by many transplant centers to be ineligible due to chronologic age—may in fact now be candidates for HCT.

The Fred Hutchinson Cancer Research Center provides an online HCT-CI calculator.

Disease stage, previous treatments (chemotherapy/radiation), infectious disease and transfusion history can also have a significant impact on HCT outcomes. Research shows that early referral is an important step that can affect survival.

Three hematopoietic cell sources are used in HCT: bone marrow, peripheral blood stem cells (PBSC) and umbilical cord blood. Each source in an allogeneic transplant can come from a related or unrelated donor or cord blood unit. Most autologous transplants use PBSC for ease of collection of the cells and a more rapid hematopoietic recovery.

Recent outcome studies have demonstrated that related and unrelated donor transplant outcomes are comparable in many patient populations. Therefore, lack of a related donor should not preclude referral for a transplant consultation. [10]

In addition, research into the use of mismatched unrelated donors (MMUD) using post-transplant cyclophosphamide (PTCy) prophylaxis has demonstrated that MMUD HCT can be used safely and effectively. [11-14] That raises the likelihood of finding a suitable donor to nearly 100% regardless of ancestry, allowing more patients to have access to HCT—especially those with diverse ancestry who often don’t have a full donor match on international registries. [15]

Because appropriate planning and early donor identification are critical for optimal outcomes, early referral for a transplant consultation is appropriate, even for patients who ultimately may never need HCT.

A psychosocial evaluation is important to assessing a patient's ability to undergo a transplant. The primary goal of the assessment is to manage any psychosocial issues that would interfere with the transplant procedure and the recovery phase. [1-3]

Due to the often-lengthy recovery period, most transplant centers require a caregiver to advocate for the patient and to be available to assist the patient during and after transplant.

Transplant centers in the NMDP^SM Network each have criteria for the kinds of transplants performed and diseases and ages treated.

Access individual U.S. transplant center information and outcomes.

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2. Scott BL, Sandmaier BM. The evaluation and counseling of candidates for hematopoietic cell transplantation. In: Forman SJ, Negrin RS, Antin JH, Appelbaum FR, eds. Thomas' Hematopoietic Cell Transplantation. 5th ed. Hoboken, NJ: Wiley-Blackwell; 2016: Chapter 29. Access
3. Fedele R, Salooja N, Martino M. Recommended screening and preventive evaluation practices of adult candidates for hematopoietic stem cell transplantation. Expert Opin Biol Ther. 2016; 16(11): 1361-1372. Access
4. Sorror ML, Storb RF, Sandmaier BM, et al. Comorbidity-age index: a clinical measure of biologic age before allogeneic hematopoietic cell transplantation. J Clin Oncol. 2014; 32(29): 3249-3256. Access
5. Rashidi A, Ebadi E, Colditz GA, DiPersio JF. Outcomes of allogeneic stem cell transplantation in elderly patients with acute myeloid leukemia: A systematic review and meta-analysis. Biol Blood Marrow Transplant. 2016; 22(4): 651-657. Access
6. Abel GA, Klepin HD. Frailty and the management of hematologic malignancies. Blood. 2018; 131(5): 515-524. Access
7. Sorror ML. How I assess comorbidities before hematopoietic cell transplantation. Blood. 2013; 121(15): 2854-2863. Access
8. Sorror ML, Maris MB, Storb R, et al. Hematopoietic cell transplantation (HCT)-specific comorbidity index: A new tool for risk assessment before allogeneic HCT. Blood. 2005; 106(8): 2912-2919. Access
9. McClune BL, Weisdorf DJ, Pedersen TL, et al. Effect of age on outcome of reduced-intensity hematopoietic cell transplantation for older patients with acute myeloid leukemia in first complete remission or with myelodysplastic syndrome. J Clin Oncol. 2010; 28(11): 1878-1887. Access
10. Horowitz MM. Does matched unrelated donor transplantation have the same outcome as matched sibling transplantation in unselected patients? Best Pract Res Clin Haematol. 2012;25(4):483–486. Access
11. Shaw BE, Jimenez-Jimenez AM, Burns LJ, et al. National Marrow Donor Program–Sponsored Multicenter, Phase II Trial of HLA-Mismatched Unrelated Donor Bone Marrow Transplantation Using Post-Transplant Cyclophosphamide. J Clin Oncol. 2021;39(18):1971-1982. Access
12. Al Malki MM, Bo-Subait S, Logan B, et al. Post-Transplant Cyclophosphamide-Based Graft-Versus-Host Disease Prophylaxis After Mismatched Unrelated Donor Peripheral Blood Stem Cell Transplantation. J Clin Oncol. 2025;43(25):2772-2781. Access
13. Shaffer BC, Gooptu M, DeFor T, et al. Post-Transplant Cyclophosphamide–Based Graft-Versus-Host Disease Prophylaxis Attenuates Disparity in Outcomes Between Use of Matched or Mismatched Unrelated Donors. J Clin Oncol. 2024;42(28):3277-3286. Access
14. Al Malki MM, Bo-Subait, Logan B, et al. Mismatching of unrelated donors beyond a single HLA-locus does not adversely impact outcomes at one year following transplantation: Results from the NMDP sponsored ACCESS study. Blood. 2025;146(Supplement 1):936. Access
15. Chowdhury AS, Maiers M, Spellman SR, Deshpande T, Bolon Y, Devine SM. Existence of HLA-Mismatched Unrelated Donors Closes the Gap in Donor Availability Regardless of Recipient Ancestry. Transplant Cell Ther. 2023;29(11):686.e1-686.e8. Access