Center News

Time bomb ticking inside the mouth

July 5, 2001
teen receiving dental exam

Pre-transplant patient Toya Leonce, 15, of Kent, opens wide for a dental checkup from Alliance dental hygenist Monica Standaert-Askins. Leonce has chronic myeloid leukemia.

Photo by Clay Eals

Excessive plaque buildup. Gingivitis. Deep periodontal pockets. Failing root canals. All common dental problems that generally are routinely managed and often resolved by a routine trip to the dentist's chair.

But for a patient about to undergo a stem cell transplant, these seemingly trivial problems and discomforts may lurk as a time bomb ticking inside the mouth.

Oral mucositis - a potentially severe inflammation and ulceration of the moist tissue lining the oral cavity - is one of the most debilitating side effects reported by transplant patients and can be exacerbated by preexisting dental disease and conditions, said Dr. Mark Schubert, director of Oral Medicine at the Seattle Cancer Care Alliance.

"Our responsibility is to get patients' oral health as stable as we can before they begin the conditioning regimen for transplantation," he said. "Even normal oral bacteria can cause major problems when the patient is immunocompro-mised, leading to potentially severe infections and significant follow-up care."

Schubert has hard data to back up these claims. He co-wrote a study of transplant patients at the Hutch and other cancer centers, published in the April 15 Journal of Clinical Oncology, showing that oral mucositis may significantly increase infection and hospital stay, resulting in an average of about $43,000 in added hospital charges per patient.

The enormous impact of oral mucositis on the success of a transplant warrants a visit to the dentist's chair from every transplant patient before, during and after his or her therapy. With the formation of the Alliance, Schubert said that medical oncology patients undergoing treatment for cancers other than leukemia sometimes make a stop in one of his two examination rooms on the sixth floor as well.

"Any intense chemotherapy or radiation can cause oral problems," he said, "but because the immune system is destroyed as part of the conditioning regimen for transplantation, the problems are most severe for those patients."

Constant cell turnover

The reason for the complications, Schubert said, is that the oral mucosa requires constant turnover of cells. Chemotherapy and radiation can interfere with the normal replenishment of cells, leading to ulceration. Without a healthy immune system, the stage is set for host of bacterial, fungal and viral infections.

"We all have bacteria that live inside our mouths," said Schubert, who has degrees in dentistry and oral medicine. "But if there is a way for them to gain entry into the blood, even the bugs that are normally harmless can cause serious problems."

Particularly worrisome, he said, is the potential systemic spread of infection to various organs - infections that can ultimately be devastating.

Schubert describes his role as an unusual one that is "smack-dab in the middle between medicine and dentistry."

To head off problems before they start, his department gives every transplant patient a checkup, including a panoramic X-ray and oral exam.

"We attempt to get rid of any active infection and sources of trauma or irritation," said Schubert, who works with dental hygienists Michelle Lloid, who also serves as manager, and Monica Standaert-Askins and dental assistant Huddle Blakefield.

"We'll do some limited oral surgery and restorative care," he said, "but for anything more involved we now refer patients to Dr. Bart Johnson and the hospital dentists at the University of Washington. With the Alliance and the expanded ability to easily draw upon dental services at the UW Medical Center and School of Dentistry, we can better provide more comprehensive pre-transplant care to patients with extensive dental problems."

After the intense conditioning chemotherapy and radiation given before transplant in order to destroy leukemic marrow, low white blood cell and platelet counts make oral infections and bleeding a risk for several weeks.

Later in the process, Schubert said, graft-vs.-host-disease - a potentially serious complication in which donor immune cells attack the recipient's tissues -also can lead to oral lesions. Some patients experience long-term GVHD and may have months or years of oral complications.

While preventive oral care may not eliminate oral mucositis as a side effect of transplantation, it can minimize the severity of the symptoms and associated disability.

"If you ask transplant recipients to name the worst part of their early transplant experience, oral mucositis makes it to the top of the list," Schubert said. "It can cause dry mouth, stinging and burning and serious pain. Some patients are unable to swallow and require intravenous feeding."

Because an immunocompromised state can persist for months after a transplant, patients must be taught how to care for their teeth and mouth to minimize occurrence of infection.

"We instruct patients not to get their teeth cleaned at the dentist's office for six to nine months after transplant," Schubert said. "With the immune system still recovering, the spraying and splashing involved with routine dental treatment can result in patients inhaling bacteria and debris that can significantly increase the risk of pneumonia. And if patients have graft-vs.-host disease, routine dental treatment often needs to be delayed longer."

None of this knowledge came quickly or easily. Schubert has been involved with Hutch patients since 1975 - when he was called in from UW to consult on a case - and his tenure here has contributed toward a wealth of information about how to best care for the patients' oral health.

"I grew up, so to speak, with bone marrow transplantation," he said. "When I started, there was no info or literature out there about any of this."

85 percent with transplant

His infrequent consultations became more regular, and he now spends about 85 percent of his time with the transplant program, with the remainder spent at the UW, where he is a professor of oral medicine in the School of Dentistry. At the Alliance, he supervises a staff of four, plus research assistants and oral medicine fellows.

"We've come a long way since part of our facilities were located in a hallway," he said with a laugh. "We're grateful that we have such an excellent facility here in the new Alliance outpatient clinic."

When patients can't come to his exam room, he and his staff make the rounds on inpatient wards at UW and at Children's Hospital and Regional Medical Center.

"I've been lucky to have a dedicated, hardworking staff," he said. "It can be difficult to see patients going through cancer therapy, but my staff is committed to providing the best care they can."

In addition to patient care, an important part of his job is to help train UW oral medicine students and graduates as specialists in the needs of cancer patients.

Schubert also considers research a priority, having participated in studies to evaluate new therapies to minimize oral mucositis. Recently, he worked with oral specialists around the country to develop a scoring system to measure the extent and severity of oral mucositis as a tool to aid research on this complication.

The research not only leads to improved patient outcomes but also helps to educate insurance companies that paying for transplant-related oral care is a wise investment.

Fred Hutchinson Cancer Research Center is a world leader in research to prevent, detect and treat cancer and other life-threatening diseases.