The CHEK2*1100delC allelic variant and risk of breast cancer: screening results from the Breast Cancer Family Registry.
CHEK2, a serine-threonine kinase, is activated in response to agents, such as ionizing radiation, which induce DNA double-strand breaks. Activation of CHEK2 can result in cell cycle checkpoint arrest or apoptosis. One specific variant, CHEK2*1100delC, has been associated with an increased risk of breast cancer. In this population-based study, we screened 2,311 female breast cancer cases and 496 general population controls enrolled in the Ontario and Northern California Breast Cancer Family Registries for this variant (all controls were Canadian). Overall, 30 cases and one control carried the 1100delC allele. In Ontario, the weighted mutation carrier frequency among cases and controls was 1.34% and 0.20%, respectively [odds ratio (OR), 6.65; 95% confidence interval (95% CI), 2.37-18.68]. In California, the weighted population mutation carrier frequency in cases was 0.40%. Across all cases, 1 of 524 non-Caucasians (0.19%) and 29 of 1,775 Caucasians (1.63%) were mutation carriers (OR, 0.12; 95% CI, 0.02-0.89). Among Caucasian cases >45 years age at diagnosis, carrier status was associated with history of benign breast disease (OR, 3.18; 95% CI, 1.30-7.80) and exposure to diagnostic ionizing radiation (excluding mammography; OR, 3.21; 95% CI, 1.13-9.14); compared with women without exposure to ionizing radiation, the association was strongest among women exposed >15 years before diagnosis (OR, 4.28; 95% CI, 1.50-12.20) and among those who received two or more chest X-rays (OR, 3.63; 95% CI, 1.25-10.52). These data supporting the biological relevance of CHEK2 in breast carcinogenesis suggest that further studies examining the joint roles of CHEK2*1100delC carrier status and radiation exposure may be warranted.
Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, 3rd Floor, 307 East 63rd Street, New York, New York 10021, USA. bernstej@mskcc.org
Jonine L
JL
Bernstein
Sharon N
SN
Teraoka
Esther M
EM
John
Irene L
IL
Andrulis
Julia A
JA
Knight
Robert
R
Lapinski
Eric R
ER
Olson
Abigail L
AL
Wolitzer
Daniela
D
Seminara
Alice S
AS
Whittemore
Patrick
P
Concannon
D000328:Adult; D000368:Aged; D000483:Alleles; D017209:Apoptosis / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics*; D002140:California; D016022:Case-Control Studies; D064447:Checkpoint Kinase 2; D005260:Female; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D009864:Ontario; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D013902:Radiography, Thoracic / Q000009:adverse effects*; D012042:Registries; D012307:Risk Factors
D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases