We all carry the same genes. Some of those genes are responsible for cell division in certain areas of our bodies.
Mutations in HBOC syndrome genes greatly affect a person's ability to ward off or fight breast, ovarian and prostate cancer. Depending on the mutation carried, a person may also be at risk of some other types of cancer.
HBOC syndrome causes high risk of breast, ovarian and prostate cancer and slightly higher risk of some other types of cancer.
Hereditary cancer is a relatively new science. Hereditary breast cancer, the first to fall under HBOC syndrome, was discovered in 1995 with mutations in the BR(east)CA(ancer)1 gene. Soon after mutations were also discovered in the BRCA2 gene and it became known that other types of cancer were involved. For years researchers focused on the BRCA genes but more recently, many additional risky genes were discovered that also fall under HBOC syndrome. Most of the research that drives today's recommendations is only about the BRCA genes and because researchers are constantly learning more, cancer risk statistics can vary, sometimes widely, depending on the source.
With more than 1,200 different types of mutations discovered to date in each of the BRCA genes alone, researchers do not yet have enough information to stratify cancer risk for those genes, nor for any of the newer HBOC syndrome genes.
It is important to know that hereditary cancer risk statistics tend to be reported in broad averages. Personal cancer risk can fall well below or above those average ranges. For example, if a table shows the top-end cancer risk for BRCA1 as 65% for breast cancer, this does not mean the highest cancer risk a certain individual will experience is 65%.
Personal cancer risk must be determined by a trained professional. Cancer risk is based on the HBOC syndrome gene that is mutated, the particular mutation within that gene, the number of first-degree relatives with cancer and a variety of other factors.
Learn more about additional cancer risk factors
Some ethnic groups are known to have a higher chance of carrying certain risky genes than in the general population. For example, people of Ashkenazi (Eastern European) Jewish ancestry have a 1 in 40 chance of carrying one of three founder BRCA mutations associated with that population. Other ethnic groups include, but are not limited to: French Canadian, Bahamian, Polish, Icelandic and African American.