(August 21, 2015) A study published online in JAMA Oncology this month shows that screening women with a suspected risk of hereditary breast or ovarian cancer with a multigene panel (which looks for mutations in many genes), identifies more people with cancer risk related gene mutations than screening for BRCA1 and 2 alone. Importantly, identifying these additional gene mutations provides clinically useful information which would likely impact medical options for the majority of these patients and families.
In the study of over 1,000 women, 3.8% or 40 patients, who were negative for BRCA 1/2 mutations did have harmful mutations of hereditary cancer predisposition genes, including in genes for ovarian, breast and colorectal cancer. A 3.8% prevalence of additional mutations represented a greater than 40% increase in the diagnostic yield of risk-associated mutations compared with BRCA 1/2 testing alone.
Overall, 52% of patients in whom a mutation was identified would be recommended for additional screening or preventive measures above and beyond what would be called for by personal and family history. In addition, the presence of the mutations would lead to recommendations that close female relatives of 72% of the patients also be screened for the mutations, which if present would change their recommended clinical management as well.
“The traditional approach has been to test most women with suspected hereditary risk for breast and/or ovarian cancer for BRCA1/2 alone,” explains senior author Leif Ellisen, MD, PhD of Massachusetts General Hospital. “The concern about broader testing has been that the results really wouldn’t change what we told women about their risk and management – either because the risk associated with the other genes are not as high as for BRCA1/2 or because the clinical practice guidelines associated with other genes are less specific. Our study shows that, even under current practice guidelines, finding mutations in these other genes is likely to change the clinical management recommendations both for patients and for family members who also carry the associated mutations.”
OCRF Scientific Advisory Committee member Elizabeth Swisher, MD commented on the study, saying, “Multigene testing is rapidly becoming the norm for genetic cancer risk assessment. We must continue to assess the effect of such testing on clinical care and patient experience and work to provide meaningful guidelines for cancer-preventive care for those with less common genetic findings.”