St. Jude Children’s Research Hospital researchers have evidence that common genetic variations can help to identify pediatric cancer survivors who are at increased risk for developing breast cancer while relatively young. The findings appear today in the journal Clinical Cancer Research.

The research focused on the combined effect of 170 common genetic variations that individually confer a modest increased risk of breast cancer. The research showed for the first time that, together, they can leave female pediatric cancer survivors at as much as a two-fold increased risk of breast cancer compared to average survivors. The risk is greatest for survivors less than 45 years old.

“Female survivors of childhood cancer have among the highest rates of breast cancer of any group,” said lead author Zhaoming Wang, PhD, an associate member of the St. Jude Department of Epidemiology and Cancer Control and the Department of Computational Biology. That risk has mainly been attributed to the late effects of pediatric cancer treatment, particularly chest irradiation, certain chemotherapy exposures, or the presence of rare mutations in breast cancer susceptibility genes.

For survivors at some of the highest risk, the collective effect of the common genetic variants is comparable to having a high-risk mutation in a breast cancer predisposition gene like BRCA1 or BRCA2, Wang said. The mutations are associated with a 2- to 100-fold increased breast cancer risk.

“This study provides a more complete picture of genetic breast cancer susceptibility among childhood cancer survivors,” Wang said. “When combined with screening for rare mutations in breast cancer predisposition genes, these findings are expected to help identify high-risk pediatric cancer survivors who currently go unrecognized.

“The findings also suggest that personalized breast cancer surveillance and prevention for childhood cancer survivors is on the horizon,” he said.

—Newswise