Women who have a faulty version of the CHEK2 gene called CHEK2*1100delC have double the chance of developing breast cancer when compared with non-carriers. But the gene variant could confer a greater risk in women with a family history of the disease, particularly those with a family history of bilateral breast cancer (cancer affecting both breasts).
Julian Peto (The London School of Hygiene and Tropical Medicine, UK) and colleagues tested 469 patients with bilateral breast cancer for the CHEK2*1100delC variant. They then analysed the risk of breast cancer, prostate cancer, and all other cancers in first-degree relatives of carriers and non-carriers. The investigators found that first-degree relatives of women who have bilateral breast cancer and a normal version of CHEK2 had a cumulative breast cancer risk of 23.8% by age 80 years compared with an expected cumulative risk of 7.9%. However, for relatives of women with bilateral breast cancer and the CHEK2*1100delC mutation the cumulative risk by age 80 was 58.8%.
Study author Olivia Fletcher (The London School of Hygiene and Tropical Medicine, UK) states: "Roughly 2000 bilateral breast cancer cases are diagnosed in the UK every year, of whom 2% are carriers of CHEK2*110delC. Testing for CHEK2*1100delC in women with a family history of breast cancer, especially those with a bilaterally affected first-degree relative, could be clinically useful for predicting personal risks."
Contact: Sally Staples in the Cancer Research UK press office. T) 020 7061 8300 or, out of hours, the duty press officer on 07050 264059.
Emma Sheppard in the Breakthrough Breast Cancer press office. T) 020 7025 2488/ 0777 868 2001 emmas@breakthrough.org.uk
Journal
The Lancet