Hepatoblastoma

SAN FRANCISCO -- Half of young adult survivors of pediatric solid cancers had low bone mineral density and nearly a fourth had suffered at least one fracture since completion of their treatment, according to a cross-sectional study conducted at the State University of New York-Syracuse Health Sciences Center.

"Young adult survivors of pediatric solid tumors appear to be at increased risk of developing at least regional osteopenia or osteoporosis," concluded Dr. Timothy A. Damron, professor of orthopedic surgery at the university.

Dr. Damron and associates reported on the first 38 patients enrolled in a follow-up study of pediatric cancer survivors.

Some survivors of childhood cancers are known to be at risk for low bone mineral density (BMD), including those who had brain tumors, acute lymphocytic leukemia, cranial radiation, or nonautologous bone marrow transplantation. "Less well established is the risk among survivors of solid pediatric cancers," he said at the annual meeting of the American Academy of Orthopaedic Surgeons.

The first patients in the registry include 17 survivors of lymphoma, 8 survivors of sarcoma, 5 survivors of Wilm's tumor, 4 survivors of neuroblastoma, and 1 survivor each of ovarian germ cell tumor, yolk sac carcinoma. Triton tumor, and hepatoblastoma.

The mean age of the subjects at follow-up was 22, and they were first diagnosed with cancer at a mean age of 8.9 years. Thirty-six patients had received chemotherapy, 13 in combination with radiation therapy. Two had only radiation therapy for non-Hodgkin's lymphoma.

The study involved an analysis of risk factors for osteoporosis and a dual-energy x-ray absorptiometry scan for each subject that consisted of the following readings: total body, lumbar spine, bilateral total hip, femoral neck, and distal radius. Osteopenia was defined as a Z score less than -1.0; osteoporosis was defined as a Z score of -2.0 or less.

Low BMD at one or more sites was found in 19 of 38 survivors. Seven had osteoporosis by study criteria, and 12 had osteopenia. One patient had total body osteopenia. Six patients had low BMD isolated to the upper extremities.

Nine patients had suffered a fracture after completion of cancer treatment, including five in an area identified by the follow-up study as having low BMD.

Low BMD was found in every survivor of bone sarcoma and no survivors of soft tissue sarcoma, he said.

"Our multivariate statistical analysis failed to reveal a relationship of any single [chemotherapeutic] agent or duration of [cancer] therapy, but we did find a direct relationship with the number of chemotherapy drugs administered," said Dr. Damron. "As the number of chemotherapy drugs increased, so did osteoporosis or osteopenia."

The largest published study to date of BMD in survivors of solid tumor cancers found a 65% rate of osteoporosis or osteopenia in 48 subjects. "We had a lower incidence of low bone mineral density, but at a much lower age [mean age 22 years, compared with 31 years] and somewhat shorter duration of follow-up" (mean 12.6 years, compared with 16 years), he said.

BY BETSY BATES

Los Angeles Bureau

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