'Reassuring' study shows deaths from childhood cancer declining
Recent public concern about a possible increase in the incidence of childhood cancers was spurred, at least in part, by Jonathan Harr's 1995 book, A Civil Action. In his book--a best-seller and the basis for a 1998 movie--Harr told the story of the families of eight pediatric leukemia patients in Woburn, Massachusetts, who decided to sue two major corporations for dumping chemicals into their town's water supply.
Now, in a study that one public health expert has called "marvelously reassuring," a group of researchers from the National Cancer Institute (NCI) has reported that death rates from all major types of childhood cancers declined steadily between 1975 and 1995. The new study ("Cancer Surveillance Series: Recent Trends in Childhood Cancer Incidence and Mortality in the United States") was published in the June 16, 1999, issue of the Journal of the National Cancer Institute.
According to John P. Morgan M.D., a professor of pharmacology at the medical school of the City University of New York (CUNY) and a scientific advisor to the American Council on Science and Health, a New York-based public health education group, "people are afraid of chemicals, of radiation, and of cell phones; and we need more work like this study to help people think more clearly."
Comparing the period 1993-1995 with the period 1975-1977, the NCI researchers found that total childhood cancer mortality declined by 58 percent. Between 1975 and 1995 more than 14,500 cancers were diagnosed among American children younger than age 15. The cancers were reported to nine population-based registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. The three major childhood cancers diagnosed most frequently during the 20-year period were leukemias, central nervous system (CNS) cancers (cancers of the brain and spinal cord), and lymphomas (cancers of the white blood cells that are part of the body's immune system).
According to the study, the mortality rates for leukemias, for CNS cancers, and for all other childhood cancers combined decreased 52 percent, 20 percent, and 59 percent, respectively, over the period surveyed. The NCI researchers also found that the number of new cases of most childhood cancers remained stable, save for a modest (and as yet unexplainable) decline in Hodgkin's disease and slight increases in two rare cancers, adrenal neuroblastoma and dermatofibrosarcoma.
The study's lead author, Martha S. Linet M.D. of the National Cancer Institute in Bethesda, Maryland, stated in an interview that "the steady decline in childhood cancer [death] rates is certainly good news, since these declines correlate with improvements in survival." Noting that the cause of the majority of childhood cancers remains unknown, Linet concluded that "childhood cancer trends in the United States should continue to be monitored, and postulated risk factors (including environmental exposures) should be evaluated to identify the causes of cancer in children."
Commenting further on the study, CUNY's Morgan pointed out that "this paper gives us reason to question the idea that an increase in childhood cancer is due to exposure to environmental toxins." "In that sense," he added, "it is a marvelously reassuring paper."
Dr. Elizabeth M. Whelan is president of the American Council on Science and Health, a nonprofit, consumer education organization dedicated to providing the public with mainstream scientific information on issues related to food, nutrition, chemicals, pharmaceuticals, lifestyle, the environment, and health. She can be reached by email at email@example.com.