When Angelina Jolie publicly shared that she carries a BRCA1 mutation, it sparked a global conversation about inherited cancer risk. This mutation informed her that she had an 87% risk of developing breast cancer later in life, leading to her decision for breast surgery. Importantly, this test did not tell her she had cancer. It told her she had an increased risk of developing cancer in the future. [1]

That distinction highlights an important shift in cancer care.

Historically, cancer has often been diagnosed only after symptoms appear. Today, advances in next-generation sequencing (NGS) allow us to look earlier.

Some tests identify inherited risk factors that may increase the likelihood of developing cancer. Others look for molecular signs that cancer may already be present before symptoms emerge.

Both are designed to create opportunities for earlier action.

Cancer Risk Testing

Cancer risk tests analyze germline DNA, the genetic information you inherit at birth. These tests are typically performed once in a lifetime because this DNA remains largely unchanged throughout life.

These tests identify inherited variants that may give the cancer a “head start”. The BRCA1 mutation carried by Angelina Jolie is one example. Individuals who inherit variants in genes such as BRCA1, BRCA2, or those associated with Lynch syndrome may face substantially elevated cancer risks.

Not all cancer that appears to run in families is hereditary. Experts estimate that only about 5% to 10% of cancers are caused by inherited mutations, while another 15% to 20% are considered familial, reflecting a combination of shared genetics, environmental exposures, lifestyle factors, and other influences. [2]

When an inherited risk factor is identified, the goal is prevention through earlier screening, increased surveillance, or other risk-reduction strategies.

A hereditary cancer finding may also have implications beyond the individual. Because inherited variants can be passed from parent to child, genetic testing results may help inform healthcare decisions for family members as well.

Cancer Screening

A common misconception is that the difference between hereditary testing and cancer screening lies in the mutation itself. In reality, it lies in the source of the genetic material being analyzed.

While germline testing examines inherited DNA from normal cells, cancer screening examines DNA or RNA that may originate from tumor cells.

Because cancer can develop over time, screening is designed to be repeated at regular intervals. A negative result today cannot guarantee that cancer will not develop in the future.

Two Paths to Earlier Detection

Although they answer different questions, cancer risk testing and cancer screening share a common goal: identifying opportunities to act before symptoms appear.

Someone who learns they carry an inherited cancer predisposition may choose to pursue more intensive screening. Conversely, a cancer detected through screening may prompt genetic testing to determine whether family members could also be at increased risk.

Together, these approaches offer a more complete strategy for cancer prevention and early detection.

References

1. Cancer Research UK. Angelina Jolie, inherited breast cancer and the BRCA1 gene. Published May 14, 2013. Accessed June 9, 2026. https://news.cancerresearchuk.org/2013/05/14/angelina-jolie-inherited-breast-cancer-and-the-brca1-gene/

2. Memorial Sloan Kettering Cancer Center. Frequently Asked Questions About Hereditary Cancers. Accessed June 9, 2026. https://www.mskcc.org/cancer-care/cancer-risk-and-cancer-screening/genetic-counseling-and-testing/frequently-asked-questions-about-hereditary