BRCA1 Mutation Not Always Harmful

A new study published by Cell Reports found that the BRCA1 gene is necessary for the survival of stem cells that mature into blood cells. These findings may explain why patients with mutated BRCA1 do not have a high risk of developing leukemia, since the stem cells die prior to turning into cancerous blood cells.

“One of the great mysteries in cancer research is why inherited mutations, such as those in BRCA1, cause cancer only in specific tissues such as the breast and ovaries, rather than in all tissues. Our data suggest a ‘die or transform’ hypothesis, which could explain this tissue specificity,” said researcher Theodora Ross, MD, PhD.

The authors also found that these patients may also experience more adverse events related to chemotherapy, and plan to explore this association in further studies.

“Patients with certain BRCA1 mutations may be at a higher than expected risk for serious complications during chemotherapy treatment,” Dr Ross said. “If we confirm these clinical findings in upcoming studies, giving patients preventative antibiotics or growth factors may be necessary to lower this increased risk of treatment side effects.”

More than 246,660 women will be diagnosed with breast cancer, and 22,280 women will be diagnosed with ovarian cancer this year, according to the National Cancer Institute. Up to 15% of these cases will be driven by BRCA1 and BRCA2 mutations.

Traditionally, mutations in the BRCA1 gene are associated with an increased risk of developing female reproductive cancers. However, this new research indicates that not all mutations are harmful, and in fact, some can even lower the risk of certain cancers.

“Our data also illustrate why rare variations in the BRCA1 gene are not always mutations that put women and men at high risk for specific cancers,” Dr Ross said. “We and others have learned that most rare ‘spellings’ of the BRCA1 gene, spellings we call variations of undetermined significance, are not harmful.”