Breast Cancer and Genetics

17 Aug 2015 in

In true Hollywood fashion, when a celebrity speaks the masses listen.

That’s precisely what happened when Angelina Jolie penned an editorial in The New York Times that shined the spotlight on breast cancer and genetics, specifically genes that can cause the disease.

Quickly dubbed the “Angelina Jolie Effect,” the number of women requesting a blood test to reveal if they’re carriers of the BRCA1 and BRCA2 genes has nearly doubled since the editorial’s 2013 publication, according to various studies including one by the online journal Breast Cancer Research.

Although inherited factors account for less than 5 percent of breast cancer cases, individuals who carry the BRCA1 and BRCA2 mutations live with a more than 70 percent risk of developing breast or ovarian cancer, according to the World Health Organization.

As Jolie explained, after tests revealed she carried the mutations, along with an 87 percent risk of developing breast cancer and 50 percent of ovarian, she decided to be proactive and underwent a prophylactic double mastectomy.

Yet, finding out that you aren’t a carrier of BRCA mutations doesn’t mean you’re home free. Actually, the BRCA mutations only account for 50 percent of all hereditary breast cancers. That’s why a recent study published in The American Society of Breast Surgeons revealed that multi-panel gene testing is much more effective, potentially identifying up to seven genetic mutations that may lead to hereditary breast cancer.

The study evaluated the rates of pathogenic or disease causing mutations and Variants of Uncertain Significance (VUS) detected in 629 patients tested for BRCA1 and BRCA2, compared to 337 who underwent multi-gene panel testing. The majority of patients had a personal and family history of breast cancer and were Caucasian.

Initiated after concerns were raised that the tests solely dedicated to BRCA1 and BRCA2 genes were unable to detect all harmful mutations, the study concluded that patients at risk for hereditary breast cancer can safely benefit from multi-gene panel testing, considering it detects both the BRCA mutations, in addition to non-BRCA genes.

The U.S. Supreme Court ruling of Association for Molecular Pathology v. Myriad Genetics, Inc. opened the doors for competition in the genetic testing market. The landmark 2013 decision, which held that naturally occurring DNA cannot be subject to patents, invalidated many patents that had previously restricted BRCA1 and BRCA2. That ruling enabled these companies to begin offering multi-gene panel testing instead of multiple rounds of sequential testing gene-by-gene.

Breast Cancer and Genetics

While the “Angelina Jolie Effect,” has no doubt resulted in more awareness of genetic breast cancer, it has also caused unnecessary stress and concern for some women.

Many patients now approach their physicians requesting genetic testing. Family history and genetics do play a part in breast cancer, for example individuals of Ashkenazi Jewish descent are more likely to be carriers of the BRCA mutations, yet only 10 percent of breast cancers are related to inherited mutations.

Finding out whether you qualify for genetic testing is the first step. If you do, your sample will be collected via blood or buccal swab. Expect to receive results within three to four weeks.

Whether or not you possess an inherited mutation, preventative care is crucial. Women without family histories of the disease should begin receiving regular mammograms at the age of 40. And self-breast exams are essential.

Breast cancer tops the charts as the second leading cause of cancer death among American women with an estimated 40,000 dying of the disease in 2014 alone, according to the National Cancer Institute.


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