Pediatric oncologist Emmanuel Katsanis: Transforming cancer care for Arizona’s youth

Emmanuel Katsanis, MD, still remembers the names of the first children he treated in his initial rotations in hematology oncology pediatrics at the University of Ottawa in Canada.

As a young resident, he found himself caring for children with cancer, particularly acute lymphoblastic leukemia, the most common pediatric malignancy.

“One of those patients, a young, 7-year-old girl, ended up requiring a bone marrow transplant,” he said. “Back then, our children’s hospital was new, so she was one of the first two patients who had a transplant there. Without a pediatric transplant physician on staff, just pediatric oncologists, an adult transplanter guided our team. When I finished my residency, I knew I wanted to specialize in that field.”

Katsanis came to Arizona 28 years ago and has led the University of Arizona Comprehensive Cancer Center’s Hematopoietic Cell Transplantation and Cellular Therapy Program as its program director since 2012. He is also the chief of the University of Arizona and Banner Health Pediatric Hematology and Oncology Division for Tucson and Phoenix.

He holds the Louise Thomas Endowed Chair in Pediatric Cancer Research, the Peter and Paula Fasseas Endowed Chair in Cancer Research, is a faculty member at the U of A College of Medicine; a member of the Steele Children’s Research Center and BIO5 Institute; and is a faculty mentor in the Graduate Interdisciplinary Program in Cancer Biology and Immunobiology.

“When I came here, the opportunities were great, not only clinically where there was a big need in my field, but also in research,” Katsanis said. “It was a very collaborative environment.”

Launch into hematology-oncology and hemopoietic cell transplantation pediatrics

Katsanis began his medical school experience in Athens, Greece. There, he met many thalassemia patients, which sparked his interest in hematology.

Thalassemia is an inherited blood disorder where the body produces an abnormal hemoglobin, which is essential for red blood cells to carry oxygen. This leads to anemia and other health problems and iron overload due to chronic transfusions.

“Back then, the patients I saw were both teenagers and young adults requiring many transfusions,” he said. “With all the transfusions they had, they began having organ failure from iron overload, as there were no drugs back then that could help those patients eliminate the iron in their blood.”

Katsanis said thalassemia patients died in their 20s at that time without today’s care options.

“I saw a lot of those patients, and I developed an interest in hematology at that point,” he said.

Following his return to Canada, where he was born, and his exposure to pediatric oncology and bone marrow transplantation during his pediatric residency, he moved to the University of Minnesota in 1987—home to the largest pediatric BMT program at the time—to train in the field.

Strides in transplantation in Arizona

Since 1997, Katsanis has treated children, adolescents and young adults with blood disorders and cancer at Diamond Children’s Center at Banner Health, and he has seen extraordinary changes in the field.

For patients with leukemia, treatment is extensive. They may require hematopoietic stem cell transplant, commonly known as a bone marrow transplant, which replaces a cancer patient’s bone marrow with healthy stem cells and a new immune system. They first receive high dose chemotherapy drugs, and possibly total body irradiation, to eliminate the diseased cells in their immune system. They are then administered a dose of donor stem cells, which engraft into the bone marrow and grow to build a healthy system that can fight cancer.

Katsanis said that process is effective because it allows higher doses of chemotherapy, and the patient gets a new immune system from the donor, which may recognize the cancer as foreign and attack it in a process called graft versus leukemia.

“The immune system may play a significant role in eliminating any cancer cells surviving chemotherapy,” Katsanis said.

Since 2010, the pediatric transplant program has grown from eight transplants to 31 in the past year, with a greater than 90% one-year survival rate during the last five years.

“Transplant has evolved significantly,” he said. “The outcomes are not what they used to be when I first started in this area. Only about half of the patients survived, and now, for many patients, one can expect cure rates of greater than 80%.”

Development of haploidentical transplantation

One of the greatest breakthroughs Katsanis has led is the use of haploidentical transplantation, which allows a parent, child, or half-matched relative to serve as a donor when a fully matched sibling, found in only about one in four cases, is not available.

The program began in 2014 to give more children access to lifesaving transplants, especially those from minority backgrounds who are less likely to find a donor. Today, his team of six pediatric oncologists and six pediatric oncology nurse practitioners, including two dedicated exclusively to transplant, care for these patients.

With the program now expanded to Phoenix, Katsanis emphasizes how haploidentical transplants have opened the door to cures for children who once had no options.

“Haploidentical transplant is relatively new, even though it was tried many years ago when I first started in the field, but with a lot of complications, so it was largely abandoned,” Katsanis said. “Then about 15 years ago, the transplant group at Johns Hopkins showed that you can give chemotherapy through a drug called cyclophosphamide, which is a common chemotherapeutic agent. By using cyclophosphamide early after transplantation, it eliminates the alloreactive T lymphocytes, that potentially would cause lethal graft versus host disease that occurs when the donor's immune system attacks the patient.”

The cancer center’s clinical partner, Banner Health, has one of the largest pediatric haplo-BMT footprints in the country, having completed over 70 haploidentical transplants for a variety of leukemias and many benign, non-malignant hematologic disorders. About 35% of all transplant patients come from the Phoenix area.

“Using half matches has really increased the number of donors that we have and how fast you can move into a transplant,” Katsanis said. “Half matches are easy to find because both parents are always half matches, and if a sibling is not a full match, there is a 50% chance that they’re a half match with the patient,” Katsanis said. “Even though unrelated transplants have been great resource, if you need a transplant urgently because a patient may relapse, the family is there and willing to go ahead quickly. It's been a lifesaver for many patients in Arizona.”

Adding to the team’s success is the addition of the new Banner Health Diamond Children’s cancer center, a children’s hematology and oncology treatment clinic built in 2021 which remains the only pediatric oncology and hematology outpatient cancer clinic in southern Arizona.

“If we take all pediatric cancers in the last 30 years or so, we have gone from approximately 60% overall survival to 85%,” he said. “For bone marrow transplantation cases we usually get, the patients have failed all the other therapies, so these are challenging cases, mostly children with relapsed or refractory leukemias."

Impact of immunotherapy and research

Another important discovery in cancer is immunotherapy, including the use of Chimeric Antigen Receptor T-cell therapy, called CAR T cells, that use the patient’s own genetically modified T cells to fight their cancer. This therapy is effective in achieving remission and can also be used as a bridge to transplantation.

“CAR T-cells were first applied in 2012 to a young girl at Children's Hospital of Philadelphia, who had failed all other therapies,” Katsanis said. “They were expecting her to die, and she was cured with CAR T-cells, which led to rapid approval of this therapy by the FDA.”

Katsanis said that engineering CAR T-cells to recognize the patient's leukemia takes about a month. After that, the cells are shipped back from the laboratory, infused into the patient, and they find their way to the leukemia and induce remission.

Katsanis noted that while CAR T-cell therapy has shown effectiveness, sustaining long-term remission remains a challenge for many patients. His approach is often to proceed to transplantation while the patient is still in remission, as bone marrow transplantation offers higher cure rates.

“It’s not only the newer therapies, but also major advances in supportive care,” Katsanis said. “We now have more effective antibiotics, antivirals, and antifungals, along with improved methods to detect infections early. In addition, the progress across all the subspecialties has been remarkable. Together, these advances allow us to cure patients far more effectively than we could 30 years ago.”