What Are Leukemia and Lymphoma and How Are They Treated?

Breakthroughs in cancer treatment are not always single, big events. Sometimes they are gradual, progressing over years following research and results of clinical trials. Treatments for leukemia and lymphoma are like that, with the most recent innovations revolving around boosting the immune system itself to fight cancer and transplanting healthy cells into the body to replace those that are cancerous.

Cellular therapy is the umbrella term that includes the transplants – called stem cell transplants or bone marrow transplants – as well as a variety of cell-based treatments that enhance the immune system. These treatments are part of the Stem Cell Transplant and Cellular Therapy program at Lehigh Valley Topper Cancer Institute.

These two diseases are referenced together because they are both considered cancers of the blood. However, they are different.

Leukemia is uncontrolled growth of blood cells in the bone marrow, where the body’s blood is made. Lymphoma originates in the white blood cells and affects the lymphatic system, the body's germ-fighting and disease-fighting immune system. When it comes to treatment for these cancers, there is some overlap.  

Treatment for lymphoma may include radiation, chemotherapy, immunotherapy, targeted therapy and/or stem cell transplants. Sometimes, a combination of treatments is used. “It really depends on the type of disease,” says Jordan Mellinger Kish, director of the Stem Cell Transplant and Cellular Therapy program at Lehigh Valley Topper Cancer Institute. “Lymphoma has different genetic mutations, and the mutations determine the treatment.”

For leukemia, it’s a little different. “Chemotherapy alone will not always cure leukemia,” Mellinger Kish says. “For most people with acute leukemia, the objective is to get the disease under control – with chemotherapy – and then proceed with a transplant, which offers the best chance for a cure.”

Prior to a stem cell transplant, high doses of chemotherapy are used to destroy the cancer cells in the patient’s bone marrow. Those cells are replaced with new, healthy blood-forming stem cells. Most transplants use immature peripheral blood stem cells from the patient’s bloodstream. Others use bone marrow or umbilical cord blood stem cells, from the patient or donated. These then grow and multiply creating new cells and new bone marrow.

On the other hand, the broader cellular therapies, such as chimeric antigen receptor T-cell (CAR-T) therapy and tumor infiltrating lymphocyte (TIL) therapy,  involve other kinds of cells, like T cells and B cells, which are white blood cells that help your immune system fight disease.

These cells are used to attack the tumor. Cellular therapy may also involve tumor cells that have been reengineered to encourage an immune-system attack. Unlike the cells used in a bone marrow transplant, these cells are altered or programmed before being returned, by infusion, back into the patient’s body.

Not everyone can undergo stem cell transplantation and cellular therapy. An oncologist might refer a patient, but they must meet certain criteria. This includes the disease itself, the patient’s age and an evaluation to determine if the patient is physically and mentally capable of undergoing the demands of the treatment. “More than 30 patients have been referred in the last few months, and unfortunately many were not eligible or appropriate for a transplant,” Mellinger Kish says.

At this point, stem cell transplants are “tried-and-true” treatments for cancers such as multiple myeloma, Hodgkin lymphoma, non-Hodgkin lymphoma and leukemia. Cellular therapy, specifically the novel CAR-T, has been FDA-approved for treating lymphoma and multiple myeloma.

The Cancer Institute’s Stem Cell Transplant and Cellular Therapy program, started in 2023, is one of only 15 to 20 in the United States. The program was approved for stem cell transplants by the Department of Health in January 2024 and is on its way to being accredited by the Foundation for the Accreditation of Cellular Therapy (FACT). To be eligible for accreditation, a minimum of 10 stem cell transplants must have been completed in a 12-month period, depending on the type of accreditation sought.

The team is looking ahead to regulatory approval for CAR-T therapy in fall 2024 and TIL therapy in spring 2025.

“There are lots of clinical trials happening to see if CAR-T and TIL are effective for other cancers and diseases. We’re excited to be at the leading edge of offering more options for our patients,” Mellinger Kish says.