Study: Skin cancer among women with an inherited BRCA mutation

Relevance: Medium-High

Strength of Science: Medium

Research Timeline: Human Research

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What is this study about?

In the general population, risk factors for skin cancer include the amount of sun exposure, fair skin, lighter eye color and a family history of skin cancer.

Inherited mutations in several genes have been shown to increase the risk of skin cancer. However, it is unclear if an inherited BRCA1 or BRCA2 mutation increases the risk of skin cancer.

What is this study about?

Researchers of this study wanted to know if having a BRCA1 or BRCA2 mutation increases risk of skin cancer and melanoma.

Why is this study important?
Women who have an inherited mutation in BRCA1 or BRCA2 have an increased risk of several cancers, including breast, ovarian, fallopian tube, peritoneal and pancreatic cancers. However, research on whether having a BRCA mutation increases the risk of skin cancer, specifically melanoma, has been conflicting. Because of this uncertainty, people with inherited BRCA mutations question when and how often they should be screened for skin cancer.

Study findings

Researchers followed 6,207 women with an inherited mutation in BRCA1 (3,623) or BRCA2 (2,584).  The average age of participants was 55. All participants lived in North America (in the United States or Canada).

Women were followed for an average of eight years. The average age at follow-up was 55.

• 232 women reported a diagnosis of any skin cancer. 
  • 133 had a BRCA1 mutation.
  • 99 had a BRCA2 mutation.
• In this study, the lifetime risk of any skin cancer was:
  • 14.1% for BRCA1 mutation carriers.
  • 10.7% for BRCA2 mutation carriers.

These risks are similar to the lifetime risk of any skin cancer among women in the general population.

• 44 women reported a diagnosis of melanoma.
  • 23 had a BRCA1 mutation.
  • 21 had a BRCA2 mutation.
• In this study, the lifetime risk of melanoma was:
  • 2.5% for BRCA1 mutation carriers.
  • 2.3% for BRCA2 mutation carriers.

The lifetime risk of melanoma among BRCA1 or BRCA2 mutation carriers was slightly higher than the lifetime risk in the general population.  The risk is 1.5 percent in the general population compared to 2.5 percent for women with a BRCA1 mutation and 2.3 percent for women with a BRCA2 mutation.

Lifetime risk of skin cancer

Skin cancer rates increase with age. In this study, skin cancer rates were highest after age 70.

When researchers looked at previous cancers among participants, the lifetime risk of any skin cancer increased after a breast cancer diagnosis only among BRCA1 mutation carriers.

Other skin cancer genes

The table below lists genes that are linked to an increased skin cancer risk.

What does this mean for me?

The increased lifetime risk of melanoma among BRCA1 and BRCA2 mutation carriers is slightly higher than the risk of individuals who are not BRCA1 or BRCA2 mutation carriers. Currently, the National Comprehensive Cancer Network (NCCN) does not offer specific screening guidelines for melanoma for people with an inherited mutation in BRCA1 or BRCA2. However, some experts recommend general melanoma risk management, such as a yearly full-body skin exam, a yearly eye exam (melanoma can occur in the eye) and avoiding too much sun exposure. During a skin cancer screening, show your doctors any suspicious moles or areas of your skin that look concerning or have changed color or appearance.

Hallmarks of skin cancer include the ABCDE signs: Asymmetry, Borders that are irregular, multiple Colors, Diameter of over 6 millimeter and Evolving or changing in size, shape or color:

If you have a personal or family history of melanoma and you are concerned about increased risk, consider talking to a healthcare provider about mutations in genes other than BRCA1 and BRCA2 that may increase your risk of melanoma.

Reference:

Narod, S.A., Metcalfe, K., Finch, A. et al. The risk of skin cancer in women who carry BRCA1 or BRCA2 mutations. Hereditary Cancer Clinical Practice. 2024. 22(1): 7.

Disclosure: FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.

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posted 7/25/24