NBN gene

Associated Syndrome Name: NBN-associated Cancer Risk

NBN Summary Cancer Risk Table

Cancer Genetic Cancer Risk
BreastElevated Risk
ProstateElevated Risk

NBN gene Overview

NBN-associated Cancer Risk 1, 2, 3, 4, 5
  • Women with NBN mutations may have a risk for breast cancer that is increased over the 12.5% lifetime risk for women in the general population of the United States.
  • Men with mutations in the NBN gene are may have an increased risk for prostate cancer.
  • NBN mutations are most common in patients of Slavic ancestry, where a single founder mutation (c.657_661del) is estimated to be present in 1:167 individuals. Evidence for increased female breast cancer and male prostate cancer risks are mostly based on studies of individuals of Eastern European ancestry with this specific mutation, and these risks may not apply to other NBN mutations or patients of other ancestries.
  • It has been suggested that patients with NBN mutations have an increased risk for cancers other than breast and prostate cancer. In particular, there is evidence for an association with pediatric leukemias and lymphomas. The data for this are not conclusive at this time and there are no current medical management recommendations associated with pediatric cancer risk for carriers of NBN mutations.
  • Although there may be increased risks for cancer in men and women with mutations in NBN, there are interventions that may reduce these risks. Guidelines from the National Comprehensive Cancer Network (NCCN) that may apply are listed below. Since information about the cancer risks associated with NBN mutations is relatively new, and there is still some uncertainty about the best ways to reduce these risks, it may be appropriate to interpret these results in consultation with cancer genetics experts in this emerging area of knowledge.

NBN gene Cancer Risk Table

Cancer Type Age Range Cancer Risk Risk for General Population
Female BreastTo age 803, 4, 6Possibly elevated risk10.7%
ProstateTo age 801, 2, 6Possibly elevated risk10.5%

NBN Cancer Risk Management Table

The overview of medical management options provided is a summary of professional society guidelines. The most recent version of each guideline should be consulted for more detailed and up-to-date information before developing a treatment plan for a particular patient.

This overview is provided for informational purposes only and does not constitute a recommendation. While the medical society guidelines summarized herein provide important and useful information, medical management decisions for any particular patient should be made in consultation between that patient and his or her healthcare provider and may differ from society guidelines based on a complete understanding of the patient’s personal medical history, surgeries and other treatments.

Cancer Type Procedure Age to Begin Frequency
(Unless otherwise indicated by findings)
Female BreastCurrently there are no specific medical management guidelines for breast cancer risk in mutation carriers. However, the possibility of an increased risk for breast cancer warrants consideration of individualized breast cancer risk-reduction strategies, such as the modification of standard population screening recommendations by starting screening at younger ages, performing screenings at greater frequency, and utilizing more sensitive technologies such as breast MRI.IndividualizedNA
ProstateCurrently there are no specific medical management guidelines for prostate cancer risk in mutation carriers. However, the possibility of an increased risk for prostate cancer can be incorporated into the risk and benefit discussion about offering screening with digital rectal examination (DRE) and Prostate Specific Antigen (PSA).745 years, or youngerIndividualized

Information for Family Members

The following information for Family Members will appear as part of the MMT for a patient found to have a mutation in the NBN gene.

This patient's relatives are at risk for carrying the same mutation(s) and associated cancer risks as this patient. Cancer risks for females and males who have this/these mutation(s) are provided below.

Family members should talk to a healthcare provider about genetic testing. Close relatives such as parents, children, brothers and sisters have the highest chance of having the same mutation(s) as this patient. Other more distant relatives such as cousins, aunts, uncles, and grandparents also have a chance of carrying the same mutation(s). Testing of at-risk relatives can identify those family members with the same mutation(s) who may benefit from surveillance and early intervention.

In rare instances, an individual may inherit mutations in both copies of the NBN gene, leading to the condition Nijmegen Breakage Syndrome (NBS). Individuals with NBS will have growth retardation, immunodeficiency, and a greatly increased risk for varied types of cancer diagnosed at young ages. The children of this patient are at risk of inheriting NBS only if the other parent is also a carrier of an NBN mutation. Screening the other biological parent of any children for NBN mutations may be appropriate, particularly if they are of Eastern European ancestry, since NBN mutations are more common in this group.5

References

  1. Cybulski C, et al. An inherited NBN mutation is associated with poor prognosis prostate cancer. Br J Cancer. 2013 108:461-8. PMID: 23149842.
  2. Cybulski C, et al. NBS1 is a prostate cancer susceptibility gene. Cancer Res. 2004 64:1215-9. PMID: 14973119.
  3. Zhang B, et al. Genetic variants associated with breast-cancer risk: comprehensive research synopsis, meta-analysis, and epidemiological evidence. Lancet Oncol. 2011 12:477-88. PMID: 21514219.
  4. Steffen J, et al. Germline mutations 657del5 of the NBS1 gene contribute significantly to the incidence of breast cancer in Central Poland. Int J Cancer. 2006 119:472-5. PMID: 16770759.
  5. Varon R, et al. Nijmegen Breakage Syndrome. 2017 Feb 2. In: Pagon RA, et al., editors. GeneReviews® [Internet]. PMID: 20301355.
  6. SEER*Explorer: An interactive website for SEER cancer statistics [Internet]. Surveillance Research Program, National Cancer Institute. [Cited 2023 Mar 24]. Available from https://seer.cancer.gov/explorer/.
  7. Moses KA, et al. NCCN Clinical Practice Guidelines in Oncology®: Prostate Cancer Early Detection. V 1.2023. Jan 9. Available at https://www.nccn.org.
Last Updated on 31-Jan-2024