Erin Sweeney

Tempe girl is among the first in nation to benefit from new prosthetic device that grows with her.

Childhood is full of bumps and bruises. So when Terri Sweeney noticed a small lump on her 10-year-old daughter Erin's right leg, she wasn't worried.

"We assumed Erin had fallen at school," says Terri.

But two weeks later, the lump had grown. Erin's leg had swollen, and she was in pain. Terri took Erin to see their family physician in Tempe, Ariz. After examining X-rays of Erin's leg, the physician referred Erin to an orthopedic surgeon, who in turn referred her to Mayo Clinic for more thorough testing.

The Sweeneys met with Christopher Beauchamp, M.D., an orthopedic surgeon at Mayo Clinic Arizona. After examining Erin and reviewing her tests, Dr. Beauchamp told the Sweeneys that the lump on Erin's leg could be a number of things, including a tumor.

"We hadn't even been thinking of cancer," says Terri. "You don't want to think about that, so you focus on other potential causes."

But on June 11, 2002, less than a month after first noticing the lump on Erin's leg, Terri and her husband, Tim, were forced to confront their worst fears. "Dr. Beauchamp called us into his office to give us the results of Erin's biopsy," says Tim. "I could see in his eyes that something was wrong."

A biopsy revealed that Erin had osteosarcoma — a rare bone cancer that affects about 600 children and adolescents each year in the United States. The lump on Erin's leg was a result of a malignant tumor on her femur.

"We were devastated," says Tim. "Cancer just wasn't one of the possibilities we had considered."

It wasn't a possibility Erin had considered, either. "When I heard I had cancer, I was scared," says Erin, now 11 years old. "My grandma had cancer, and she died. I didn't know what to think."

When Dr. Beauchamp explained Erin's treatment options, the Sweeneys were dealt a second blow. Because this cancer affected the bone, standard treatment for children with osteosarcoma included either total or partial amputation of the leg. A third treatment option involved removing a portion of the bone of the leg and replacing it with a prosthetic device. That option, however, would mean additional surgeries to insert longer prosthetics as Erin grew, and it would be possible that she would eventually lose her leg to infections that can come with multiple surgeries.

The Sweeneys were determined that Erin would not lose her leg. "She was only 10 years old and had a life to lead," says Terri. Keeping Erin's life as normal as possible would take determination, willingness to take a risk, and being in the right place at the right time.

The first step

Regardless of the surgical treatment option the Sweeneys would eventually choose, Erin first needed chemotherapy to shrink the tumor in her leg. So while her friends prepared for a new school year, Erin began receiving chemotherapy at Phoenix Children's Hospital.

"I was in the hospital quite a bit," remembers Erin. "Even though chemo was painful, I tried to forget about it and just have fun. I knew I had a lot of people who cared about me and who were praying for me. And I had my animals — four cats and three dogs — to support me."

When Erin was hospitalized, Terri and Tim took turns spending the night at the hospital. They'd sleep in a chair beside Erin's bed, dreaming of a miracle. During the day, Terri would search the Internet, desperate to learn as much as she could about osteosarcoma.

"Everyone told me not to search the Internet because I would find bad information," says Terri. "And they were right. I found a lot of upsetting information."

But Terri also found what she had been dreaming of: a way to possibly save Erin's leg.

Her Internet research eventually led her to a prosthetic device called Repiphysis that promised to "grow" with the patient. The implant, which was not yet available in the United States, is attached to the patient's bone in the same way as other prosthetic devices. But while other prosthetics must be replaced with longer prosthetics as a child grows, this one contains a heat-activated spring that allows it to expand and lengthen within the child's leg.

After the prosthetic is implanted, the patient visits her physician at regular intervals, and the physician uses electromagnetic energy to trigger the prosthetic to expand. The physician holds an electromagnetic coil around the child's leg, which heats the plastic around the spring, allowing it to uncoil just enough — usually 8 millimeters — to accommodate the child's growth.

Bringing new technology to patient care

"A version of Repiphysis had been used in France, but the U.S. version had not yet received Food and Drug Administration (FDA) approval at the time Erin was diagnosed," says Dr. Beauchamp. After determining that this expandable prosthetic would be a good option for Erin, Dr. Beauchamp began the process of gaining special approval, both within Mayo Clinic and through the FDA, to use the device.

"We were very fortunate in that Mayo's Institutional Review Board and the FDA both worked quickly to approve the use of Repiphysis," says Dr. Beauchamp. "Both bodies recognized that there was an immediate humanitarian need for the device."

On Oct. 9, 2002, Erin was admitted to Mayo Clinic Hospital in Phoenix, where Dr. Beauchamp removed the tumor in her leg. He then implanted the prosthetic device, replacing the part of Erin's femur that was removed during surgery. Erin was the first person in Arizona — and one of the first in the nation — to receive the Repiphysis implant.

Erin, her family and her physician were anxious to find out how Erin's "new" leg would perform, but she was only midway through her treatment. She still had seven rounds of chemotherapy to complete. That meant four more months of being in and out of the hospital. Four more months of being too sick to eat. Four more months away from friends at school.

While she wouldn't want to live those months over, Erin says there was some good that came out of them. "My brothers and I became a lot closer," she says of brothers Patrick, 25, and Sean, 22. "After my diagnosis, they started taking me to movies and doing a lot more with me than with their friends."

Erin finished her last chemotherapy treatments more than a year ago.

"She's doing really well," says Terri. "She's back to being a normal kid. We're so grateful to Dr. Beauchamp. He's a fantastic doctor and a fantastic man. It is a comfort to have him taking care of Erin."

Erin's progress delights Dr. Beauchamp.

"The Repiphysis implant has made a huge difference in our ability to care for young patients with osteosarcoma," he says. "This disease used to have a high mortality rate, and was almost always treated with amputation. This device enables kids to have as normal a childhood as possible. We don't want Erin out playing contact sports, but we have to balance our desire to protect her with her desire to have fun."

Erin's new normal

Normal for Erin means returning to school, where she's on the "A" honor roll. The sixth-grader loves to read, swim and play with her friends. She even plays pickup basketball and baseball with kids in her neighborhood. "They know that I can't do everything, so they take it a little easy on me," she says.

But normal now means something else for Erin, too. Whenever she grows — which tends to be every six to eight weeks — Erin has an appointment with Dr. Beauchamp to have a lengthening procedure. The lengthening process takes less than 10 minutes and is relatively painless.

"During a lengthening, it feels like someone is tugging at my leg," says Erin. "But then I walk around for a while and it's fine."

That Erin is walking on her own leg is something her family doesn't take for granted.

"This device is a godsend," says Tim. "Everything we had heard about children and older prosthetic devices sounded terrible — multiple surgeries, infections and eventual amputation. This device enables Erin to be as close to normal as she could be. We went in for a lengthening two days before Christmas, walked out 10 minutes later, and didn't think much about it. That's amazing, considering where we were a year ago.";

A year ago, Erin celebrated her birthday on a chemotherapy ward. A year ago, she did her homework from her hospital bed. And a year ago, the Sweeneys learned the stuff their daughter was made of.

"I gained a great appreciation of my daughter," says Tim. "From the time of her diagnosis, it became obvious that she was not some little child. She made decisions about her treatment with us."

Dr. Beauchamp says that Erin "helped make it easy on everyone."

"She's a well-put-together kid," says Dr. Beauchamp. "It has been a pleasure for me to look after Erin and get to know her family. Her parents have been extremely involved in her care, always offering supportive and thoughtful contributions. I can't imagine what it's like as a parent to hear your child has cancer, and it never ceases to amaze me how strong people can be."

"There's always hope," says Tim. "The 'C' word scares people, but it can be overcome. With good medicine and strong hearts, it can be overcome."