Genetic Screening Can Predict Breast Cancer Risk

Genomic sequencing might successfully identify women who would benefit most from breast cancer screening option such as mammography. And knowing their risk for breast cancer at birth may help women take measures to modify their non-genetic risk factors, such as diet and lifestyle, and lower their risk. All this from a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

“We need low-cost screening tools that can discriminate between women who will and won’t develop fatal breast cancer that are more effective than those currently available,” said Alice S. Whittemore, PhD, professor of epidemiology and biostatistics in the Department of Health Research and Policy at Stanford Cancer Institute in California.

“Previous studies using theoretical models have predicted that sequencing the genomes of women, ranking them by risk, and then targeting those at highest risk will provide little gain in cost-effective disease prevention,” she said. “However, our estimates suggest that preventive strategies based on genome sequencing will bring greater gains in disease prevention than previously projected. Moreover, these gains will increase with increased understanding of the genetic etiology of breast cancer,” she said.

Whittemore and colleagues used data from published literature on the frequency of 86 known breast cancer variants associated with breast cancer risk. They then developed a model to estimate a woman’s lifetime probability of developing breast cancer.

“Variance is a relative measure of the heterogeneity of breast cancer risks in the population,” Whittemore said. “The more genetic variants we discover, the more heterogeneous our genetic risks will be, and the more effective it will be to target those at highest risk.”

Knowing our probability of getting cancer also might change how we live our lives, said Weiva Sieh, MD, PhD, assistant professor and epidemiologist at Stanford and first author on this study. “If a girl knew, from birth, what her inborn risk was, she could then make more informed choices to alter her future risk by altering her modifiable factors, such as diet and lifestyle.”

Source: The American Association for Cancer Research