Some Children Facing Bone Marrow Transplant Risk

The investigators found that the most common dental problem in childrenabout to undergo BMT was tooth decay, often resulting from neglectedoral hygiene and poor nutrition. Tooth decay is especially dangerous inchildren undergoing BMTs because physicians must first suppress theirimmune systems to reduce the chance of transplant rejection. Therefore,children about to undergo immunosuppression as part of BMTs should havedental checkups, said Sue C. Kaste, D.O., a member of St. JudeRadiological Sciences. "It's important to make sure they do not havecavities that could act as doorways to the bloodstream fordisease-causing bacteria," she said.

The St. Jude investigators made their findings during a retrospectivestudy of the medical records and X-rays of the entire set of teeth in259 children (age range 3.2 to 25.9 years) who underwent BMT. The mostcommon diagnosis among these children was leukemia (63 percent); whilethe other children were found to have solid tumors (14 percent), anemia(8 percent), or brain tumors (3 percent). In addition, one child hadretinoblastoma (eye cancer) and one had severe combinedimmunodeficiency. One hundred fifty of these patients were male, 203were Caucasians and 38 were African-American.

The St. Jude team found that, before BMT, 150 (57.9 percent) of the 259patients had dental abnormalities. Among patients who still had their"first" teeth before BMT, 36.4 percent had dental abnormalities; amongpatients with permanent teeth, 66.7 percent had dental abnormalities;and among patients with both first and permanent teeth, 52.3 percenthad abnormalities. There was no difference in frequency ofabnormalities in permanent teeth between males (65.5 percent) andfemales (67.5 percent), nor was there a difference between Caucasians(69 percent) and African-Americans (70 percent).

The most common dental abnormality identified in the study was caries(tooth decay), which was seen in 133 (51 percent) patients. Among otherdental problems were abnormal clumps of enamel on the tooth andcalcification (hardening) of the tooth pulp (the soft inner matter inteeth containing nerves and blood vessels).

A variety of factors can cause tooth decay in pediatric patients wholater undergo BMTs. For example, previous studies by other researchershave found that children receiving chemotherapy and radiation are atincreased risk of tooth damage that causes decay. Radiation can alsoreduce the amount of saliva released by the mouth's salivary glands,which in turn can lead to growth of decay-causing bacteria.

Some children undergoing cancer treatment also develop ulcers in thelining of their mouths, which discourage them from eating certainfoods. Instead, these children prefer sweet foods, which don't sting,but do promote tooth decay. In addition, some children undergoingcancer treatments must consume high levels of carbohydrates to ensurethey get enough calories, which also encourages the growth ofdecay-causing bacteria.

Since small cuts in the tissue around teeth caused by brushing couldbecome serious sources of blood loss, children are sometimes forbiddento brush their teeth if they suffer from severely reduced levels ofplatelets--blood cells that trigger clot formation. Finally, youngchildren often cannot brush their own teeth properly, and their parentsmight fail to brush their children's teeth.

"Our findings clearly show that children about to undergo bone marrowtransplantation should be examined for dental problems that mightpromote infections," said Christopher C. Rowland, D.D.S., the dentistin the Department of Surgery at St. Jude and a co-author of the paper."This is also an opportune time to educate patients and parents aboutproper oral hygiene. Meticulous dental care can minimize thedevelopment of therapy-related caries. Follow-up examinations aftertransplantation and immunosuppression will also help to minimizesources of potential infection."

Other authors of the paper include Mitchell D. Vaughan (University ofTennessee Health Science Center, Memphis); Xin Tong, D. KumarSrivastava, Gregory A. Hale and Richard Rochester (St. Jude).

This work was supported in part by the National Institutes of Health and ALSAC.

St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized forits pioneering work in finding cures and saving children with cancerand other catastrophic diseases. Founded by late entertainer DannyThomas and based in Memphis, Tenn., St. Jude freely shares itsdiscoveries with scientific and medical communities around the world.No family ever pays for treatments not covered by insurance, andfamilies without insurance are never asked to pay. St. Jude isfinancially supported by ALSAC, its fund-raising organization. For moreinformation, please visit www.stjude.org.