For years, researchers have known that women with a harmful mutation in BRCA genes have an elevated risk for developing hereditary breast and ovarian cancers. But a startling new study suggests that women who develop such cancers might do so at an earlier age than the generation that preceded them.
Working with women at the University of Texas' Clinical Cancer Genetics clinic, researchers compared the age of diagnosis in two generations of families with a history of BRCA-related cancer (the gene mutations are often inherited). They found that the average age of diagnosis was 48 in the older generation, but 42 in the next.
"Compared to the onset of the generation directly before them, we found a 7.9-year difference," said Dr. Jennifer Litton, who works in the department of breast medical oncology at the University of Texas' Cancer Center and is the study's lead author. "Our findings are very provocative that this is a phenomenon that we're really going to need to watch for in the next generation."
The BRCA, or breast cancer susceptibility genes, are tumor suppressors, which typically help prevent uncontrolled cellular growth. But harmful mutations in those genes have been linked with increased risk of developing breast or ovarian cancer pre-menopause.
Litton and her co-authors write in the journal Cancer that their findings support the screening recommendations of groups like the National Comprehensive Cancer Network, the nonprofit alliance of more than 20 cancer centers, which suggests screening for hereditary breast cancer should begin at age 25, or five to 10 years before the earliest age of diagnosis in a family.
"This study validates why we need to continue screening 10 years prior to the earliest onset," Litton said.
But what it does not do, she added, is explain exactly why earlier cancer onsets might be occurring. Nor does it confirm that is actually what is taking place.
"Is it that these women are actually developing cancer at an earlier age or are we just finding it earlier?" asked Susan Brown a registered nurse and the director of health education for Susan G. Komen for the Cure. "A generation ago, we didn't have genetic testing. We didn't have a different set of screening guidelines for those women. So I am not sure that this study answers that question. These may be questions for further study."
She recommended that all women make a point to learn about their family history and to consult with their provider to determine a screening plan that makes sense for them. She also cautioned that though genetic testing is relatively simple -- it is a blood test -- people should consider speaking with a geneticist or a genetic counselor before getting tested for the BRCA gene in order to understand possible ramifications.
For her part, Litton added that the new study should not cause undue panic. Indeed, according to the Mayo Clinic, BRCA gene mutations are "uncommon" and responsible for only 5 percent of breast cancers and between 10 and 15 percent of ovarian cancers.
"We are still learning quite a bit about the gene, and we are still looking for other causes of early onset cancer," she said. "This is only one small part."