Additional Information

CHEK2 gene

Associated Syndrome Name: CHEK2-associated Cancer Risk

CHEK2 Summary Cancer Risk Table

Cancer Genetic Cancer Risk
Female BreastHigh Risk
ColorectalElevated Risk
Male BreastElevated Risk

CHEK2 gene Overview

CHEK2-associated Cancer Risk 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
  • Women with CHEK2 mutations have a risk for breast cancer that is significantly increased over the 12.5% lifetime risk for women in the general population of the United States. Men with CHEK2 mutations also have an increased risk for breast cancer.
  • Estimates of cancer risk for men and women with CHEK2 mutations vary widely and are strongly influenced by family history. In cases where there is no family history of one of these cancers, the risk for a patient with a CHEK2 mutation may be lower than in cases where that cancer has been diagnosed in one or more close relatives. Therefore, the family history of a patient should be considered when deciding on the most appropriate strategies to manage cancer risk, with more aggressive strategies targeted to patients with significant family histories of related cancers.
  • Individuals with CHEK2 mutations may have an elevated risk for colorectal cancer, and the National Comprehensive Cancer Network (NCCN) has provided screening recommendations to address this possible risk.
  • Although many different CHEK2 mutations have been identified, estimated cancer risks for CHEK2 are currently based largely on studies of a single mutation (c.1100del) that is common in patients of European ancestry. These estimates may be modified as we learn more about other CHEK2 mutations in patients of varied ancestries.
  • Some studies have described a possible increased risk for a wide range of cancers in patients with CHEK2 mutations, including prostate, leukemia, lymphoma, gastric cancer, thyroid cancer and other malignancies. However, these studies are not conclusive and there are currently no medical management guidelines to address these possible risks.
  • Although there are increased risks for cancer in men and women with mutations in CHEK2, 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 CHEK2 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.

CHEK2 gene Cancer Risk Table

Cancer Type Age Range Cancer Risk Risk for General Population
Female BreastTo age 801, 2, 5, 6, 1123%-48%10.2%
Second primary within 10 years of first breast cancer diagnosis10, 12Up to 29%4.0%
Male BreastTo age 807, 110.4%-1%0.1%
ColorectalTo age 804, 11Possibly elevated risk3.0%

CHEK2 Cancer Risk Management Table

The overview of medical management options provided is a summary of professional society guidelines as of the last Myriad update shown on this page. The specific reference provided (e.g., NCCN guidelines) should be consulted for more details 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 BreastBreast awareness - Women should be familiar with their breasts and promptly report changes to their healthcare provider. Periodic, consistent breast self-examination (BSE) may facilitate breast awareness.13IndividualizedNA
Clinical encounter, including clinical breast exam, ongoing risk assessment and risk-reduction counseling13When genetic risk is identifiedEvery 6 to 12 months
Mammography with consideration of tomosynthesis and consideration of breast MRI with contrast14Age 40, or modified to a younger age based on the family history of breast cancerAnnually
Consider additional risk-reduction strategies.13, 14IndividualizedNA
Male BreastCurrently there are no specific medical management guidelines for breast cancer risk in mutation carriers. However, the increase in risk warrants consideration of options for male breast cancer screening, such as patient breast awareness education and clinical breast examinations.13, 14IndividualizedNA
ColorectalColonoscopy440 years, or 10 years younger than the age of diagnosis for any first-degree relative with colorectal cancerEvery 5 years

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 CHEK2 gene.

A major potential benefit of myRisk genetic testing for hereditary cancer risk is the opportunity to prevent cancer in relatives of patients in whom clinically significant mutations are identified. Healthcare providers have an important role in making sure that patients with clinically significant mutations are informed about the risks to relatives, and ways in which genetic testing can guide lifesaving interventions.


  1. Weischer M, et al. CHEK2*1100delC heterozygosity in women with breast cancer associated with early death, breast cancer-specific death, and increased risk of a second breast cancer. J Clin Oncol. 2012 30:4308-16. PMID: 23109706.
  2. Meijers-Heijboer H, et al. CHEK2-Breast Cancer Consortium. Low-penetrance susceptibility to breast cancer due to CHEK2(*)1100delC in noncarriers of BRCA1 or BRCA2 mutations. Nat Genet. 2002 31:55-9. PMID: 11967536.
  3. Teodorczyk U, et al. The risk of gastric cancer in carriers of CHEK2 mutations. Fam Cancer. 2013 12:473-8. PMID: 23296741.
  4. Provenzale D, et al. NCCN Clinical Practice Guidelines in Oncology® Genetic/Familial High-Risk Assessment: Colorectal. V 1.2018. July 12. Available at
  5. Weischer et al. CHEK2*1100delC genotyping for clinical assessment of breast cancer risk: meta-analyses of 26,000 patient cases and 27,000 controls. J Clin Oncol. 2008 26: 542-8. PMID: 18172190.
  6. CHEK2 Breast Cancer Case-Control Consortium. CHEK2*1100delC and susceptibility to breast cancer: a collaborative analysis involving 10,860 breast cancer cases and 9,065 controls from 10 studies. Am J Hum Genet. 2004 74:1175-82. PMID: 15122511.
  7. Wasielewski M, et al. CHEK2 1100delC and male breast cancer in the Netherlands. Breast Cancer Res Treat. 2009 116:397-400. PMID: 18759107.
  8. Cybulski C, et al. A large germline deletion in the CHEK2 kinase gene is associated with an increased risk of prostate cancer. J Med Genet. 2006 43:863-6. PMID: 17085682.
  9. Xiang HP, et al. Meta-analysis of CHEK2 1100delC variant and colorectal cancer susceptibility. Eur J Cancer. 2011 47:2546-51. PMID: 21807500.
  10. Kriege M, et al. Survival and contralateral breast cancer in CHEK2 1100delC breast cancer patients: impact of adjuvant chemotherapy. Br J Cancer. 2014. 111:1004-13. PMID: 24918820.
  11. Fast Stats: An interactive tool for access to SEER cancer statistics. Surveillance Research Program, National Cancer Institute. (Accessed on 1-2-2017)
  12. Curtis RE, et al. New Malignancies Following Breast Cancer. 2006 In: Curtis RE, et al., editors. New Malignancies Among Cancer Survivors: SEER Cancer Registries, 1973-2000. National Cancer Institute. NIH Publ. No. 05-5302.
  13. Bevers TB, et al. NCCN Clinical Practice Guidelines in Oncology®: Breast Cancer Screening and Diagnosis. V 2.2018. May 18. Available at
  14. Daly M et al. NCCN Clinical Practice Guidelines in Oncology®: Genetic/Familial High-Risk Assessment: Breast and Ovarian. V 2.2019. July 30. Available at
Last Updated on 09-Jul-2019