Living on Borrowed Strength
An ingenious transplant therapy lets doctors harness one person’s immune system to fight another person’s cancer.
In September 2001, Jonell Shoemaker began experiencing unexplained bruising. Her doctor referred her to Froedtert & Medical College of Wisconsin, where physicians diagnosed her with acute myeloid leukemia and recommended an intriguing new therapy. They proposed attacking the cancer with the power of the immune system. Not her immune system — someone else’s.
The therapy is known as a non-myeloablative transplant or, more commonly, a “mini-transplant.” It’s an ingenious twist on the conventional blood and bone marrow transplants that have been part of cancer care for decades.
Tantalizing Side EffectBlood and marrow transplants were introduced in the 1960s as a follow-up to high-dose chemotherapy treatment. According to James Wade, MD, MPH, high-dose chemo is like a nuclear bomb — it destroys not only cancer cells, but the patient’s bone marrow and immune system as well. The only way to rebuild this crucial system after treatment is to give the patient an infusion of adult blood stem cells or bone marrow cells.
Dr. Wade, a Medical College of Wisconsin medical oncologist and chief of Neoplastic Diseases and Related Disorders at Froedtert & Medical College of Wisconsin, explains that with a standard bone marrow transplant, patients can receive their own cells or cells donated by another person. Transplanted donor cells have the advantage of being able to attack cancer, but they can also cause Graft Versus Host Disease, or GVHD. With GVHD, donated blood cells attack the patient.
From the early days of donor cell transplants, physicians wrestled with the sometimes deadly symptoms of GVHD, but they also noted one tantalizing side effect — patients who receive donor cells are more likely to remain cancer-free. Eventually, researchers discovered why: Although donor cells can attack the patient, they also attack any leftover cancer cells.
Physicians soon realized that harnessing this reaction would create a new way to fight cancer. The idea of the mini-transplant was born.
Waiting for a ReactionAfter she was diagnosed, Shoemaker sought out several second opinions around the country and spent time investigating her options. A search of the medical literature proved revealing. “When it came to mini-transplants, I found Froedtert & MedicalCollege of Wisconsin was on the cutting edge in research and treatment.” She decided Froedtert was the place to be. Her physician was Mary Horowitz, MD, MS, a Medical College of Wisconsin medical oncologist. According to Dr. Horowitz, step one of a mini-transplant is a very low dose of chemotherapy or radiation. The purpose is not to kill the cancer, but simply to suppress the patient’s immune system so the donated blood or marrow can go to work. After this initial dose, the patient receives the donated cells through an IV infusion.
“This is a high-risk time for the patient,” says Dr. Horowitz, who thinks a better term for the therapy is reduced-intensity transplant. To help make sure the immune reaction does not get out of control, the patient takes anti-rejection drugs and other medications. Everyone watches for signs of GVHD. Gradually, says Dr. Horowitz, donor cells repopulate the blood system, hopefully destroying any cancer cells. The whole process takes six to twelve months.
Shoemaker’s mini-transplant took place in September 2002. After chemotherapyand a dose of radiation, she received cells donated by her brother. Periodic bloodtests tracked the amount of donor cells in her blood. “Once the cells started multiplying,” says Shoemaker, “they went from zero to 100% in a couple months.” She never experienced any adverse symptoms.
“Stardust in the Bag”One important issue with mini-transplants is finding a suitable donor. Shoemaker was among the 30% of people who have a sibling with a sufficiently close “tissue type.” (“My brother was almost a perfect match,” she says. “That was our stardustin the bag!”) Another 30% to 40% of patients can be linked with an unrelated donor. The remaining are ineligible for the treatment.
Since the cancer-killing effect of a minitransplant is gradual, the therapy is best suited to slow-growing malignancies. It is often recommended for older people who are not strong enough for high-dose chemotherapy.
“To date, the diseases we can treat with a mini-transplant are still a small portion of all cancers,” says Dr. Wade, who was a member of the 1997 team that performed the world’s first mini-transplant at the Fred Hutchinson Cancer Research Center in Seattle. He says the therapy has proven effective for blood cancers like leukemia, lymphoma and multiple myeloma.
Awesome FeelingShoemaker has been off anti-rejection medications since April 2003 and is now in complete remission. She is grateful to her husband, family and friends for their devoted support during her illness, and is especially grateful to her brother. She expresses astonishment about the care she received at Froedtert & Medical College of Wisconsin.
“If I rang the bell and no one answered, it’s because a nurse was there immediately,” she says. “It sounds kind of trite, but when you are feeling that vulnerable, it was awesome.” She notes that her doctors were incredibly caring.
“I remember Dr. Horowitz stopping by to see me at 11:30 at night after finishing up some office work —s he wasn’t even on call that day!” Overall, Shoemaker was amazed at the depth and dedication of the staff. “ I tell everyone I know — if youare in trouble, get to Froedtert.”
A retired pediatric occupational therapist, Shoemaker now volunteers one day aweek at Kathy’s House, a patient hospitality residence near Froedtert & Medical College of Wisconsin. She says her biggest contribution is providing encouragement to cancer patients just starting treatment: “I am able to say that I went through it — and that there are a lot more good outcomes than there used to be.”
Source: Froedtert Today
Date: November 2004