The St. Jude Endocrine Clinic


When Trista Matlock was in the second grade, she learned how to give herself injections, using oranges as practice subjects. Today, she spends her days awash in a sea of orange, attending the University of Tennessee and occasionally working at Tennessee Sports Zone, her family’s store.

She still gives herself those injections. As a result of a brain tumor, Trista’s body does not produce the hormones she needs to grow, respond to stress or develop sexually. So for the past 13 years, she has been receiving care from endocrine clinicians at St. Jude Children’s Research Hospital. Most people don’t realize that St. Jude has an Endocrine Clinic, but Trista’s dad is a vocal advocate of the service. “If it were not for the Endocrine Clinic, Trista would now be about the same size she was when she was in the first grade,” says David Matlock.   

“When doctors found my tumor, they said it would be a miracle if I reached 5 feet tall,” says Trista, who has now surpassed that prediction by 5 inches.

Trista’s parents always knew she was one in a million, but when their daughter was in the first grade they found out that she had a disease that struck with similar odds. Trista had craniopharyngioma, a rare tumor that occurs just above the pituitary gland near the bottom of the brain. David was horrified when he learned the diagnosis. “I was scared to death to take Trista to St. Jude,” he recalls. “I thought that’s where kids go to die. It took me a while to realize that that’s where kids go to live.”

Kids at risk

Trista’s tumor and its treatment wreaked havoc on her endocrine system. This system consists of a group of structures that include the hypothalamus, pituitary, thyroid, parathyroid, adrenal, pancreas and reproductive glands. Each gland secretes chemical messengers called hormones into the bloodstream. These hormones affect almost every bodily function by transferring information from one set of cells to another. Hormones regulate growth and development, metabolism and energy, tissue function, sexual maturation and reproductive processes.

Trista experienced damage to her pituitary gland, a pea-sized structure located at the base of the brain. Often dubbed the body’s master gland, the pituitary produces growth hormone, thyroid hormone, puberty hormone and stress hormone and secretes substances that control several other endocrine glands.

The pituitary releases hormones that control the ovaries and reproductive processes; because her pituitary is damaged, Trista must take estrogen. She also lacks an adequate level of thyroid hormones, so she must take medication to combat hypothyroidism, a condition that causes fatigue, slow heart rate, weight gain and delayed puberty. If Trista were to undergo physical trauma—a car wreck or high fever, for instance—she could die from absence of stress hormones. She always keeps a supply of medication handy in case of emergency.

Randi Schreiber, physician assistant in the St. Jude Endocrine Clinic, says Trista’s problems are not unusual. Any St. Jude patient who has a brain tumor, brain tumor surgery, radiation or chemotherapy is at risk for developing an endocrine problem. The endocrine staff are currently treating about 900 patients, including many children with sickle cell disease and AIDS.

“Almost all St. Jude patients are at risk for endocrine problems,” Schreiber says. “Endocrine is actually a ‘good news’ clinic, because there are medications and other interventions available to treat almost every endocrine problem we see. Our goal is to put the body back into the state it would have been before the cancer or treatment ever happened. If patients no longer produce certain hormones, we would give them medications to replace those hormones.”

Robert Danish, MD, clinic director, says the treatment of endocrine disorders has increased as survival rates have skyrocketed. 

“Years ago, because so many children died of their cancer, no one was really concerned about long-term life issues,” he observes. “Today, it’s absolutely incredible how many children are able to survive cancer. With that has come a whole new field that deals with complications of treatment. Our presence at St. Jude means that we can provide much, much better care to cancer survivors.”

Schreiber says few cancer institutions have clinics devoted to the long-term effects of oncology treatment on the endocrine system. “Most general hospitals have endocrinology departments, but they don’t follow oncology patients exclusively; they may only have 2 to 3 percent of their patient population who have undergone cancer treatment,” she says. I don’t know of any other center besides St. Jude that specializes in endocrine-oncology.”

Because Schreiber and her colleagues see so many patients who have undergone cancer treatment, they are able to provide early diagnoses. In other institutions, endocrine problems may not be identified until they become obvious. “If the patient has symptoms, then it may be too late,” Schreiber says. “For example, if a 15-year-old first comes to us because of abnormally short stature, we may not be able to help that child grow because he or she may have completed the growth process. On the other side of the spectrum, if a patient has undiagnosed stress hormone deficiency and has a severe illness or undergoes surgery, that patient may die from organ failure because the stress hormone keeps our blood pressure from plummeting in extreme situations."

Life after treatment

Patients come to the Endocrine Clinic with a wide range of problems. They may be at risk for reduced growth rate, osteoporosis, obesity, diabetes, or early or late onset of puberty; children with Hodgkin lymphoma may experience thyroid damage; patients who have pelvic radiation may have testicular or ovarian damage; patients with certain brain tumors may develop hypothyroidism; children with damage to the pituitary may develop diabetes insipidus, a dangerous condition that causes excessive urination. The litany of possible complications goes on and on. But Schreiber cites an equally impressive list of success stories. 

Three years after completing therapy, one 19-year-old cancer survivor became so fatigued that she had to use a wheelchair and sleep about 15 hours a day, excluding naps. The Endocrine staff discovered that the young woman had a growth hormone deficiency. Even though the patient was an adult, she still needed the hormone to increase her energy levels and bone mineral density. “Now she’s active in her sorority, she has a long-term boyfriend, she’s involved in various clubs at college, and she has become very successful as a productive member of society,” reports Schreiber.

Another teenager was obese because her hypothalamus had been damaged. “She was so depressed, because she was a size 22, and she just felt terrible,” recalls Schreiber. “She never ate much—just salads—and she exercised, but she kept gaining weight.” Schreiber helped the young woman obtain special approval to take a new, experimental medication. Today, that patient is a size 12, and she feels great. Her prom picture hangs in Schreiber’s office.

Danish and Schreiber are involved in several research projects that may help future St. Jude patients. They have been heavily involved in a study involving cancer survivors and bone mineral density. Other projects still in the planning stages involve such topics as osteoporosis in patients who have HIV; a search for methods to preserve fertility in patients who receive total body radiation; and a new treatment method for chemotherapy-induced diabetes. Each of these studies will provide St. Jude researchers with the opportunity to help survivors lead healthier lives.

Going forward, giving back

“I take a gajillion pills,” says Trista, as she matter-of-factly displays her Medic Alert bracelet and sings the praises of staff members at the St. Jude Endocrine Clinic. “But I’m very fortunate. I’ve turned out pretty fair, considering.” What the self-effacing young woman fails to mention is that she sailed through high school with an A-B average. She is deeply involved at her church, and she was the top St. Jude fund-raiser at her school for six consecutive years.

“She has a normal life,” says David, who credits Schreiber and James Magness, RN, of the Endocrine Clinic for their ceaseless efforts on her behalf. “When Trista would have problems, they would work with us to switch and swap medicines around until we would finally get the dosage amounts just right,” he says. “I just can’t say enough good things about them.”

Trista counts Schreiber as one of her favorite people at St. Jude. “She’s so sweet and understanding, and she relates so well to me,” says Trista, who also treasures her relationships with other staff members at the institution. “Even when I was a child and they were sticking me with needles, I loved the people at St. Jude. As a child, I always dreamed of working there.”

The long-time patient is now transforming that dream into reality. She has enrolled in college at—naturally—the University of Tennessee, Martin. “I don’t think I’ll ever be able to repay St. Jude for what they’ve done for me,” Trista says, “but I’m going to try. I’m going to be a St. Jude nurse.”

Reprinted from Promise magazine, autumn 2002