Seoul St. Mary’s: Asia’s #1 Stem Cell Transplant Center

When hematologists around the world discuss the leading bone marrow transplant (BMT) centers globally, a handful of names dominate the conversation: MD Anderson, Fred Hutchinson, Memorial Sloan Kettering, and — perhaps less familiar to Western patients but equally dominant in outcomes data — Seoul St. Mary’s Hospital. Operated by the Catholic University of Korea, Seoul St. Mary’s Catholic Hematology Hospital has performed over 30,000 hematopoietic stem cell transplants, making it the highest-volume BMT center in Asia and the fifth-largest in the world.

For international patients facing blood cancers — leukemia, lymphoma, myeloma, myelodysplastic syndromes — Seoul St. Mary’s represents a combination of world-class expertise and significantly lower costs than equivalent treatment in the United States or Europe.

The Numbers Behind the Reputation

Seoul St. Mary’s Catholic Hematology Hospital was established in 1983 and has been Korea’s national referral center for hematologic malignancies for over four decades. The scale of its operations is difficult to overstate:

• 30,000+ hematopoietic stem cell transplants performed (as of 2025)
• Approximately 700-800 transplants per year, making it one of the busiest BMT programs on Earth
• Newsweek World’s Best Hospitals 2024: Ranked #108 globally
• 1,355 beds across the hospital, with a dedicated hematology ward and transplant unit
• 5-year overall survival rates for acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) that are competitive with the top US centers

Volume matters in transplant medicine. Research consistently shows that high-volume transplant centers achieve better survival outcomes, lower complication rates, and lower transplant-related mortality. A 2021 study published in Blood found that patients treated at centers performing more than 40 allogeneic transplants per year had significantly better outcomes than those at lower-volume centers. Seoul St. Mary’s performs roughly 10 times that threshold annually.

What Conditions Does Seoul St. Mary’s Treat?

The Catholic Hematology Hospital treats the full spectrum of blood disorders and hematologic malignancies:

Blood Cancers

• Acute myeloid leukemia (AML) — the most common acute leukemia in adults
• Acute lymphoblastic leukemia (ALL) — more common in children but also affects adults
• Chronic myeloid leukemia (CML)
• Chronic lymphocytic leukemia (CLL)
• Hodgkin lymphoma
• Non-Hodgkin lymphoma (diffuse large B-cell, follicular, mantle cell, etc.)
• Multiple myeloma
• Myelodysplastic syndromes (MDS)
• Myeloproliferative neoplasms (polycythemia vera, essential thrombocythemia, myelofibrosis)

Non-Malignant Blood Disorders

• Aplastic anemia (severe and non-severe)
• Sickle cell disease
• Thalassemia major
• Inherited bone marrow failure syndromes
• Autoimmune cytopenias

Transplant Types

Seoul St. Mary’s performs all major transplant modalities:

• Autologous transplant: Using the patient’s own stem cells, typically for myeloma and certain lymphomas
• Allogeneic transplant (matched related donor): From a sibling or family member with matching HLA type
• Allogeneic transplant (matched unrelated donor): From the Korean Marrow Donor Program (KMDP) or international registries
• Haploidentical transplant: From a half-matched family member, a technique Seoul St. Mary’s has pioneered in Asia. This is particularly significant because it dramatically expands the donor pool — virtually every patient has at least one haploidentical family donor (parent, child, or sibling)
• Cord blood transplant: Using banked umbilical cord blood

Haploidentical Transplant: A Seoul St. Mary’s Specialty

One of Seoul St. Mary’s most significant contributions to hematology has been its development and refinement of haploidentical stem cell transplantation. Traditional allogeneic transplant requires a donor who matches the patient’s HLA (human leukocyte antigen) profile closely — ideally a 10/10 match. Only about 30% of patients have a fully matched sibling, and finding an unrelated donor through registries can take weeks or months, with no guarantee of a match.

Haploidentical transplant uses a donor who matches only half of the patient’s HLA markers — typically a parent, child, or half-matched sibling. The challenge has always been managing graft-versus-host disease (GVHD), where the donor’s immune cells attack the recipient’s body.

Seoul St. Mary’s has developed refined conditioning regimens, GVHD prophylaxis protocols (including post-transplant cyclophosphamide), and supportive care pathways that have brought haploidentical transplant outcomes close to those of matched donor transplants. This work has been published extensively in journals including Blood, Bone Marrow Transplantation, and Biology of Blood and Marrow Transplantation.

For international patients, haploidentical transplant means that a family member who travels with the patient can potentially serve as a donor, eliminating the uncertainty and delay of searching international registries.

CAR-T Cell Therapy

Seoul St. Mary’s has been at the forefront of CAR-T (chimeric antigen receptor T-cell) therapy adoption in Korea. CAR-T is a form of immunotherapy in which the patient’s own T-cells are genetically engineered to recognize and destroy cancer cells. It has shown remarkable response rates in certain blood cancers that have relapsed or are refractory to other treatments.

The hospital offers CAR-T therapy for:

• Relapsed/refractory diffuse large B-cell lymphoma (DLBCL)
• Relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL)
• Additional indications as approvals expand

In the United States, a single CAR-T infusion costs $373,000 to $475,000 for the therapy alone, before hospitalization, monitoring, and management of side effects (cytokine release syndrome, neurotoxicity). Total treatment costs can exceed $1 million. Korean pricing, while still significant, is substantially lower — and Seoul St. Mary’s clinical experience with managing CAR-T complications draws on its decades of transplant expertise.

Cost Comparison: Korea vs United States

Blood cancer treatment costs vary enormously depending on the specific diagnosis, treatment protocol, and complications. The following table provides approximate ranges for common scenarios:

These figures are approximate and depend heavily on the specific diagnosis, complications, length of stay, and treatment protocol. However, the pattern is consistent: treatment at Seoul St. Mary’s typically costs 30-50% of equivalent care in the United States, at a center with comparable or superior volume and outcomes for hematologic malignancies.

The Facility

Seoul St. Mary’s Hospital is located in the Seocho district of Seoul, one of the city’s most developed and accessible areas. The Catholic Hematology Hospital operates within the main campus and includes:

• Dedicated transplant unit with HEPA-filtered positive-pressure isolation rooms
• Bone marrow processing and cryopreservation laboratory
• Stem cell collection center (apheresis unit)
• Outpatient hematology clinic for pre- and post-transplant care
• Clinical trial unit for investigational therapies
• 1,355 total beds with a substantial portion allocated to hematology/oncology

The transplant isolation rooms are critical. Patients undergoing allogeneic transplant have essentially no functioning immune system for a period of weeks. The HEPA filtration and positive-pressure rooms minimize infection risk during this vulnerable period. Seoul St. Mary’s transplant unit has been designed and maintained to the same specifications as the world’s leading centers.

International Patient Services

Seoul St. Mary’s operates an International Health Care Center (IHCC) that serves as the single point of contact for foreign patients. Services include:

• Dedicated international coordinators (English, Chinese, Russian, Arabic, and other languages)
• Medical record review and pre-arrival consultation: Patients can submit their pathology reports, imaging, and treatment history for review by Seoul St. Mary’s hematologists before traveling
• Visa assistance: The hospital provides documentation to support medical visa (C-3-3 or G-1-10) applications
• Airport pickup and hospital transport
• Accommodation arrangements: The hospital can recommend nearby serviced apartments and long-stay hotels suitable for transplant patients who need to remain near the hospital for extended periods
• Interpreter services during consultations and throughout the hospital stay
• Post-discharge coordination: Follow-up schedules, medication management, and communication with the patient’s home oncologist

For transplant patients, the length of stay in Korea is significant — typically 2-4 months for the transplant itself plus immediate recovery, with ongoing follow-up visits for several months afterward. The international coordination team helps manage the logistics of an extended medical stay.

Research and Clinical Trials

Seoul St. Mary’s Catholic Hematology Hospital is not only a treatment center but also a major research institution. Its physicians have authored thousands of peer-reviewed publications in hematology and transplant medicine, and the hospital regularly participates in international clinical trials.

Areas of active research include:

• Novel GVHD prevention and treatment strategies
• Reduced-intensity conditioning regimens for older or frailer patients
• Post-transplant maintenance therapies to reduce relapse risk
• CAR-T cell therapy optimization and next-generation cellular therapies
• Minimal residual disease (MRD) monitoring using next-generation sequencing
• Cord blood expansion techniques to improve engraftment

For patients with relapsed or refractory disease who have exhausted standard options, access to clinical trials at Seoul St. Mary’s may offer additional treatment possibilities not available at their home institutions.

The Patient Experience: What International Patients Should Know

Understanding the practical realities of receiving transplant treatment at Seoul St. Mary’s helps set appropriate expectations.

Length of Stay

Bone marrow transplant is not a short-term procedure. The typical timeline for an allogeneic transplant patient:

• Pre-transplant workup: 1-2 weeks (imaging, blood work, cardiac and pulmonary function testing, dental clearance, infectious disease screening)
• Conditioning chemotherapy: 5-10 days (high-dose chemotherapy to destroy the existing bone marrow before transplant)
• Transplant day (“Day 0”): The infusion itself takes 1-4 hours, similar to a blood transfusion
• Engraftment period: 14-28 days in the hospital transplant unit, waiting for the new stem cells to establish themselves in the bone marrow and begin producing blood cells
• Post-engraftment recovery: 2-4 weeks of close outpatient monitoring after discharge, with clinic visits 2-3 times per week
• Ongoing follow-up: Weekly to monthly visits for 3-6 months post-transplant to monitor for GVHD, infections, and relapse

Total time in Korea: typically 3-6 months, depending on complications. Patients should plan for the longer end of this range.

Accommodation for Extended Stays

For a multi-month stay, the hospital’s international patient center can recommend:

• Serviced apartments near the hospital: Furnished one-bedroom apartments in Seocho (the district surrounding Seoul St. Mary’s) typically cost $1,500-$3,000 per month. These are preferable to hotels for long stays because they include kitchen facilities, laundry, and more living space.
• Goshiwon (small studio rooms): Budget option at $400-$800/month, though these are small and may not be comfortable for a patient recovering from transplant.
• Caregiver accommodation: Most serviced apartments can accommodate a companion. Having a caregiver present is strongly recommended for transplant patients, particularly during the first 2-3 months when infection risk is highest and daily support is needed.

Diet and Nutrition During Treatment

Transplant patients follow a neutropenic diet (low-bacteria diet) during the engraftment period when their immune system is essentially nonexistent. This means:

• No raw fruits or vegetables (unless peeled)
• No raw fish (sashimi, sushi) or undercooked meat
• No unpasteurized dairy
• Thoroughly cooked foods only
• Hospital meals during inpatient stay are prepared according to these guidelines

After engraftment and discharge, dietary restrictions gradually relax as the immune system recovers. Seoul has excellent options for clean, cooked meals — Korean cuisine’s emphasis on soups, stews, and grilled dishes works well within transplant dietary guidelines.

When to Consider Seoul St. Mary’s

Seoul St. Mary’s is worth considering if you or a family member:

• Has been diagnosed with a blood cancer or bone marrow disorder requiring stem cell transplant
• Faces transplant costs in the US that are prohibitive even with insurance (transplant patients routinely face $50,000-$200,000 in out-of-pocket costs in the US)
• Needs a haploidentical transplant and wants to be treated at a center with extensive experience in this technique
• Has relapsed after initial treatment and needs a high-volume center experienced in salvage therapy and second transplants
• Wants access to CAR-T cell therapy at a fraction of US pricing
• Is seeking a second opinion on a treatment plan from one of Asia’s most experienced hematology teams

The hospital also accepts referrals from oncologists and hematologists worldwide. If your treating physician is open to coordinating with Seoul St. Mary’s, the international office can facilitate case review and treatment planning before you travel.

How to Get Started

The process for international patients typically follows these steps:

1. Submit medical records for review (pathology reports, bone marrow biopsy, imaging, treatment summary)
2. Receive a preliminary treatment plan and cost estimate from the hematology team
3. Arrange travel and visa (medical visa documentation provided by the hospital)
4. Arrive in Korea for initial consultation and pre-transplant workup
5. Begin treatment according to the agreed protocol

For detailed information about Seoul St. Mary’s Hospital, or to explore treatment options for blood cancers and other diseases, visit our service pages. If you are considering a full health screening before or after your treatment, Seoul St. Mary’s also operates a health screening center.

Need help coordinating treatment at Seoul St. Mary’s? Our team in Seoul works directly with the hospital’s international office to manage every detail — from medical record submission to accommodation and translation.

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