KUALA LUMPUR, April 13 — For many Malaysians, a diagnosis of blood cancer or a serious blood disorder can feel overwhelming, not only because of the disease, but also because of the unfamiliar medical terms that quickly follow.
Families may hear about chemotherapy, stem cell transplant, and more recently, CAR-T cell therapy. While these treatments can sound daunting, haematologists say blood cancer care has advanced significantly in recent years, giving more patients a chance at recovery and longer remission, depending on their diagnosis and how their disease responds to treatment.
Dr Chang Kian Ming, a senior consultant haematologist and transplant physician at Sunway Medical Centre, Sunway City (SMC), said blood disorders can be non-cancerous or cancerous. Blood cancers include leukaemia, lymphoma, myelodysplastic syndrome and multiple myeloma.
Leukaemia typically involves the bone marrow stem cells, while lymphoma affects the lymph nodes and myeloma involves plasma cells. The Malaysia National Cancer Registry Report 2017-2021 lists leukaemia and lymphoma among the top 10 most common cancers in Malaysia.
While chemotherapy remains a cornerstone of treatment for many blood cancers, the landscape has shifted in recent years, with medical advances opening doors for patients who once had few options, especially if their disease comes back or stops responding to standard therapy.
Among the treatments that now shape modern blood cancer care are stem cell transplant, a procedure with decades of clinical history, and CAR-T cell therapy, a newer approach that uses a patient’s immune cells to fight cancer.
However, despite more options now available, Dr Chang, who has worked as a haematologist since 1992 and has been involved in stem cell transplantation since 1996, said patients and families should understand that newer does not always mean better for every case, and that treatment decisions depend on what best fits a patient’s condition.
“Stem cell transplant and CAR-T cell therapy provide different options. It’s not to say one is better than the other,” Dr Chang told CodeBlue in an interview. Dr Chang was previously national head of service and president of the Malaysian Society of Haematology.
“If a patient’s cancer is not responding to chemotherapy or radiation, and there is a specific antigen that you can target, then CAR-T is better. Where patients respond to chemotherapy, and you want to deliver higher-dose chemotherapy or you want to replace the stem cells, then stem cell transplant is better.
“There are instances where patients have failed a stem cell transplantation where you can do CAR-T therapy. There are also instances where patients have failed CAR-T therapy and you can do a stem cell transplantation. So in a sense, they are, I think, complementary.”
Most Patients Start With Chemotherapy Before Advanced Options
After a patient is diagnosed with a blood cancer such as acute leukaemia, doctors first confirm the diagnosis, usually through a bone marrow test and specialised lab work such as flow cytometry, cytogenetics and molecular testing, including next-generation sequencing.
Patients are then risk-stratified to guide treatment. Standard-risk leukaemias typically start with chemotherapy and many respond well, with some cured through chemotherapy alone.
Intermediate or high-risk patients may still begin with chemotherapy and undergo several cycles to reach remission, but are more likely to be offered an allogeneic (donor) stem cell transplant.
Donor searches often begin early, starting with siblings before looking at other family donors or unrelated donors through international registries.
CAR-T therapy usually comes later for selected blood cancers such as B-cell lymphoma, B-cell acute lymphoblastic leukaemia and multiple myeloma, particularly if the disease relapses or becomes refractory after standard treatment.
Stem Cell Transplant Can Be Curative, But Intensive
Stem cell transplantation has been used for decades and remains a cornerstone treatment for many blood cancers and serious blood disorders.
The procedure restores the bone marrow, which produces blood cells, by infusing healthy stem cells either from the patient, known as an autologous transplant, or from a suitable donor, known as an allogeneic transplant.
Before the transplant, patients typically undergo intensive treatment to suppress the cancer and make space for the new stem cells to grow.
“For instance, in a leukaemia condition, stem cell transplantation has about 30 to 40 years of experience. We know that stem cell transplantation is able to cure the cancer, so you could opt for a bone marrow stem cell transplantation,” Dr Chang said.
While it can offer long-term remission or cure, stem cell transplantation is an intensive process that requires careful preparation, close monitoring, and a recovery period.
“But a stem cell transplantation is generally a more intensive procedure,” Dr Chang said. “It requires a person who is of a certain age, usually younger, often less than 60 years old or less than 70 years old. And the patient has to have very good organ function, pertaining to the liver, the heart, or the kidney.”
Dr Chang added that the procedural mortality risk for an allogeneic transplant can range between 10 and 15 per cent, depending on the age of the patient, performance status, and organ function.
“For autologous transplant, the mortality risk from the transplant is only 1 to 2 per cent, so it’s a very safe procedure. For patients with intermediate-risk disease, 60 to 70 per cent of patients will be cured from an allogenic stem cell transplantation,” he said.
“However, in spite of our best efforts, 20 per cent of patients still relapse.”
CAR-T Needs A Target, Most Blood Cancers Still Do Not Have One
CAR-T cell therapy has emerged in recent years as a newer option that can be considered for selected patients, particularly those whose cancers do not respond to standard treatments or return after earlier therapy.
CAR-T is a form of immunotherapy that uses a patient’s own immune cells to fight cancer, but Dr Chang said it comes with a key limitation that many people may not realise.
“CAR-T requires a target. And not many cancers have a specific target or an effective target,” Dr Chang said.
CAR-T works by collecting a patient’s or donor’s T-cells, genetically modifying them in a lab so they can better recognise cancer cells, and returning them to the body to fight the disease. The treatment depends on identifying a specific marker on the cancer cell that the engineered immune cells can lock onto.
In some blood cancers, doctors have found targets that CAR-T can attack effectively, making it an option for certain lymphomas and myeloma. “Currently only the B cell lymphomas, the multiple myelomas have specific targets,” Dr Chang said.
“In cancers you can identify a particular protein, especially in our acute lymphoblastic lymphoma or B cell lymphoma, where we can safely target a protein called CD19, it makes CAR-T cell therapy very effective,” he said.
“And then in another condition, in multiple myeloma, whereby we are able to identify a specific target, like BCMA for instance, we can use it.”
But outside those conditions, CAR-T is still not widely applicable.
“The other conditions like acute myeloid leukemia (AML), T-cell acute lymphoblastic leukaemia (T-ALL), Hodgkin’s lymphoma and so forth, whereby an appropriate target has not been identified yet. These are still in clinical research,” Dr Chang said.
“So CAR-T at the moment is only applicable to a B cell lymphoma and a multiple myeloma. Transplantation is an option for most other malignant haematology conditions.”
Dr Chang said CAR-T is typically suggested after standard approaches such as chemotherapy have not worked as expected.
“At the moment, it is an option for those patients who don’t respond to chemotherapy,” he said. “If they have failed at least two cycles or two regimens and they are either relapsing or refractory, then they will be offered CAR-T.”
The outcome of CAR-T, however, depends on the disease. “For CAR-T therapy, depending on the type of diseases that they have, 60 to 70 per cent of patients will also be successfully treated,” Dr Chang said.
“But generally, about 30 to 40 per cent of patients will remain in long term disease remission. Because CAR-T is a relatively new procedure, it is unclear at this moment whether they are longstanding survivors, meaning cure rates. But at least 30 to 40 per cent of patients with lymphomas are in remission for four to five years.”
As newer therapies develop, Dr Chang said the priority for patients remains the same. Getting diagnosed early, receiving accurate testing, and starting the right treatment quickly can shape outcomes, regardless of which advanced therapy comes later.
“The first treatment should be the best treatment. If they can attain a good remission from the first treatment, then more patients get cured,” he said.
