Leukemia No Longer Incurable: 60% of Elderly Patients Achieve Remission with Stem Cell Transplants

Leukemia, once considered incurable, is now becoming a cancer with promising cure rates thanks to advances in diagnosis and treatment technologies.

Known as "blood cancer," leukemia develops when hematopoietic stem cells in the bone marrow—the body's blood-producing factory—transform into cancer cells and produce abnormal blood cells including white blood cells, red blood cells, and platelets. Unlike solid tumors that start in one organ and spread, leukemia is characterized by cancer cells already circulating throughout the body via the bloodstream at the time of diagnosis.

In the 1970s, treatment options were limited and most patients died. Today, the landscape has completely changed. Treatment success rates have risen dramatically with the development of various medications and advances in transplanting healthy hematopoietic stem cells from donors.

"Leukemia was once considered incurable, but recent advances in treatment technology have significantly improved outcomes—even elderly patients now have a 60% cure rate," said Dr. Cho Byung-sik, Director of the Leukemia Center at Seoul St. Mary's Hospital Blood Cancer Center and Professor of Hematology.

Dr. Cho will appear on Seoul Economic TV's "Master Doctors Now" program airing at 9 p.m. on the 7th to discuss the causes, symptoms, and latest treatments for leukemia.

Acute Myeloid Leukemia Common in Adults

Acute leukemia is broadly divided into acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). ALL is more common in children and responds well to chemotherapy. AML is more prevalent in adults, particularly among the elderly.

The causes of leukemia remain largely unknown. "High-dose radiation exposure, secondary leukemia following chemotherapy, and exposure to organic solvents like benzene are known risk factors," Dr. Cho said. "However, most cases develop without any such exposure history."

He added: "Leukemia risk increases with age. We believe this occurs because genetic damage to hematopoietic stem cells accumulates over time, eventually transforming them into cancer cells."

Hereditary leukemia is rare. Dr. Cho explained that genetic testing in leukemia patients is primarily conducted not to determine hereditary transmission between parents and children, but to identify genomic mutations in leukemia cells and develop treatment strategies.

Blood Tests Recommended for Recurring Anemia, Bruising, or Infections

Leukemia lacks distinctive symptoms. However, decreased red blood cells can cause fatigue and shortness of breath; low platelets can lead to bruising and bleeding; and abnormal white blood cell function can result in unexplained fevers or recurring infections.

"These symptoms can occur for other reasons, so they cannot be definitively attributed to leukemia," Dr. Cho said. "But if you experience unexplained physical abnormalities, I recommend getting a simple complete blood count (CBC) test at a nearby hospital to check for blood cell irregularities."

Stem Cell Transplants When Chemotherapy Falls Short

Chemotherapy is the standard treatment for AML, the most common form in adults. Treatment intensity varies by patient. Chromosome testing and next-generation sequencing (NGS) analysis are performed on leukemia cells obtained through bone marrow examination to classify prognosis groups (favorable, intermediate, or poor) and develop personalized treatment strategies.

"Favorable-type patients can expect cure without relapse through chemotherapy alone," Dr. Cho said. "For intermediate and poor types, we develop strategies that connect chemotherapy to allogeneic hematopoietic stem cell transplantation."

Allogeneic hematopoietic stem cell transplantation involves transplanting healthy stem cells from a donor. The process first eliminates the patient's bone marrow and leukemia cells, then infuses donor stem cells intravenously. The donor cells establish themselves in the patient's bone marrow, attacking remaining leukemia cells while generating new blood cells.

While effective, about half of transplant patients develop graft-versus-host disease (GVHD), a complication where donor immune cells attack the patient's normal tissues including skin, intestines, and liver, causing inflammatory reactions.

Treatment prospects for GVHD are improving with new medications. "First-line treatment is high-dose steroids, but the targeted immunomodulator Jakafi (JAK inhibitor) has recently expanded treatment options," Dr. Cho said. "For cases unresponsive to Jakafi, we use Rezurock (ROCK2 inhibitor). Recent insurance coverage expansion has improved treatment outcomes compared to the past."

Stem Cell Transplants Extended to Elderly Patients, Boosting Survival Rates

Previously, only young, healthy patients could undergo stem cell transplants. Now, transplants are expanding to elderly patients.

"The biggest change is that low-intensity chemotherapy conditioning regimens have made transplants possible for elderly patients," Dr. Cho said. "Expanded donor pools and advances in GVHD treatment medications have also contributed to increased transplants and survival rates among elderly patients."

He cited the introduction of targeted therapies as the key factor behind improved treatment outcomes since 2017. "For a long time, AML had few options beyond chemotherapy and transplantation. Since 2017, targeted therapies have been introduced annually, improving treatment results," Dr. Cho said. "For patients who achieve remission after chemotherapy and proceed to allogeneic transplantation, 60% can expect a cure even at advanced ages."

Regarding prevention, Dr. Cho advised: "There is no clear prevention method, but healthy lifestyle habits are important. If you experience recurring minor symptoms like unexplained fatigue, bruising, or infections, please get a blood test."

For health screenings, he recommended: "Tests vary by screening program, but you should receive a CBC test that examines white blood cells, red blood cells, and platelets together."

"Due to dramas and movies, the misconception that leukemia is a hopeless disease persists," Dr. Cho emphasized. "But advances in targeted therapy, immunotherapy, and precision medicine have made personalized treatment plans possible, and it has become a conquerable disease. The treatment process is long and difficult, but if you persevere to the end, you can overcome it."