New Model for Genetic Testing, Breast Cancer Risk

Scientists, writing in the Journal of the National Cancer Institute, believe genetic testing could significantly improve breast cancer prevention by flagging women at greatest risk.

Using mathematical computer modeling, the researchers working at The Institute of Cancer Research, in Great Britain, and the National Cancer Institute in the United States, looked at focusing on not only the BRCA1 and BRCA2 genes but also on smaller, more common, gene variants.

Key Points:

- Researchers working with theoretical computer modeling believe that genetic testing could help guide patient decisions and broader public health programs when it comes to evaluating the risk of breast cancer.

- It could also help clinicians drive home the message to patients of the importance of changing modifiable risk factors (eg, smoking) in women most at risk.

However, they didn’t just focus on the genes. The researchers also included information on a number of other risk factors and combined it with the genetic testing data. The combined data appear to provide a picture that could be predictive of a woman's likelihood of having breast cancer.

In addition to the genetic profile, the researchers included in the modeling any family history of breast cancer, age at menarche, number of births and age at first live birth, oral contraceptive use, combined menopausal therapy use, body mass index, alcohol consumption, smoking status, personal history of benign breast disease, and breast tissue density.

With these research models, doctors could predict whether a 50-year-old woman was in the most at-risk 10% of the population for the development of breast cancer, the authors said. By knowing this, clinicians could be aggressive in addressing lifestyle changes and opting for preventative treatments, they continued.

While the research focused on breast cancer, the authors noted that they are interested in building a way to show how genetic information in combination with other risk factors could provide clinicians and patients with useful risk assessments that could help in the development of public health programs and inform individual decision-making.

"Our study shows that genetic testing has the potential to improve strategies for preventing breast cancer, and suggests that multiple, small-effect genetic risk factors could be included alongside the major breast cancer genes to assess risk,” said Monserrat Garcia-Closas, professor of epidemiology at The Institute of Cancer Research, London, who led the study, in a news release.

The authors emphasized, however, that their work was theoretical and would require more study before genetic testing of this sort could be implemented in a clinical setting.