University Times

Offspring of childhood cancer survivors face no greater risk of genetic disease

Despite theoretical concerns, children born to survivors of childhood cancer face no greater risk of genetic disease than the general population, according to the largest study of its kind.

"This long-term study should dispel concerns that therapies used to treat children with cancer years ago would in turn affect their offspring," said Pitt human genetics professor John Mulvihill, senior author of a paper on the study. The paper was published in last month's American Journal of Human Genetics. "Our findings are especially important, given that now 72 percent of children affected by cancer survive after effective treatment with chemotherapy and/or radiation." The study was initiated at the National Cancer Institute in 1980 when Mulvihill was chief of clinical genetics. It included interviews with 1,062 adult survivors of cancer who were treated as children or teenagers between 1945 and 1975. The investigators assessed the survivors' 2,198 children. Their 3.4 percent frequency of genetic disease was not significantly different from the 3.1 percent rate among 4,544 children of a control population of 2,043 adults who had not been treated for cancer as children.

The study defined genetic disease as malformations or disorders known to be associated with abnormalities in the cell's chromosomes or genes.

Childhood cancer therapies that were considered potentially damaging included radiation therapy below the waist and above the knee. Physicians were concerned that this treatment could damage the genes of a child's sperm or egg cells. Researchers also considered chemotherapy with an alkylating agent potentially harmful to these cells. Alkylating agents kill cancer cells, as well as normal cells, by cutting or crosslinking the DNA within them, rendering them unable to divide into new cells.

Authors cautioned that they cannot rule out the possibility that new therapeutic agents or combinations of existing agents in higher doses now used to treat childhood cancer could permanently damage sperm and egg cells. A further national study is underway with Pitt participation.

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Disruptions in sleep may harm immune system, study finds

Western Psychiatric Institute and Clinic research shows that disruptions in sleep may weaken the immune systems of elderly widows and widowers. The study, published last month in the journal Psychosomatic Medicine, proves that maintaining good sleep is important for the elderly to stay healthy.

The study's primary author, Martica Hall, a postdoctoral fellow in Pitt's psychiatry department, said the findings show the importance of developing interventions that reduce illnesses caused by stress-related sleep disruptions.

Researchers studied 29 persons seeking treatment for bereavement-related depression. Each participant spent three nights in a sleep lab and had blood samples drawn. Analysis revealed that those with disrupted sleep had decreased levels of natural killer cells (NKCs). NKCs are part of the body's immune system and take their name from the way they help destroy illness-causing cells. A lower NKC count indicates a weakened immune system.

Although sleep disruptions associated with bereavement or other stressful events may make people more susceptible to illness, it is not yet known whether doctors can improve patients' health by improving their sleep.

"We know that it is better to treat the underlying problem, bereavement-related depression, rather than simply treat the symptom, disturbed sleep, with a sleeping pill," Hall said. "The potential health benefits of treating bereavement-related depression, including its sleep disruptions, is one of the research avenues we're now following."