A family history of breast cancer will not predict female early onset breast cancer in a population-based setting

ABSTRACT: BACKGROUND: An increased risk of breast cancer for relatives of breast cancer patients has been demonstrated in many studies, and having a relative diagnosed with breast cancer at an early age is an indication for breast cancer screening. This indication has been derived from estimates based on data from cancer-prone families or from BRCA1/2 mutation families, and might be biased because BRCA1/2 mutations explain only a small proportion of the familial clustering of breast cancer. The aim of the current study was to determine the predictive value of a family history of cancer with regard to early onset of female breast cancer in a population based setting. METHODS: An unselected sample of 1,987 women with and without breast cancer was studied with regard to the age of diagnosis of breast cancer. RESULTS: The risk of early-onset breast cancer was increased when there were: (1) at least 2 cases of female breast cancer in first-degree relatives (yes/no; HR at age 30: 3.09; 95% CI: 128-7.44), (2) at least 2 cases of female breast cancer in first or second-degree relatives under the age of 50 (yes/no; HR at age 30: 3.36; 95% CI: 1.12-10.08), (3) at least 1 case of female breast cancer under the age of 40 in a first- or second-degree relative (yes/no; HR at age 30: 2.06; 95% CI: 0.83-5.12) and (4) any case of bilateral breast cancer (yes/no; HR at age 30: 3.47; 95%: 1.33-9.05). The positive predictive value of having 2 or more of these characteristics was 13% for breast cancer before the age of 70, 11% for breast cancer before the age of 50, and 1% for breast cancer before the age of 30. CONCLUSION: Applying family history related criteria in an unselected population could result in the screening of many women who will not develop breast cancer at an early age

A family history of breast cancer will not predict female early onset breast cancer in a population-based setting-2

<p><b>Copyright information:</b></p><p>Taken from "A family history of breast cancer will not predict female early onset breast cancer in a population-based setting"</p><p>http://www.biomedcentral.com/1471-2407/8/203</p><p>BMC Cancer 2008;8():203-203.</p><p>Published online 23 Jul 2008</p><p>PMCID:PMC2515321.</p><p></p

A family history of breast cancer will not predict female early onset breast cancer in a population-based setting-0

<p><b>Copyright information:</b></p><p>Taken from "A family history of breast cancer will not predict female early onset breast cancer in a population-based setting"</p><p>http://www.biomedcentral.com/1471-2407/8/203</p><p>BMC Cancer 2008;8():203-203.</p><p>Published online 23 Jul 2008</p><p>PMCID:PMC2515321.</p><p></p

A family history of breast cancer will not predict female early onset breast cancer in a population-based setting-1

<p><b>Copyright information:</b></p><p>Taken from "A family history of breast cancer will not predict female early onset breast cancer in a population-based setting"</p><p>http://www.biomedcentral.com/1471-2407/8/203</p><p>BMC Cancer 2008;8():203-203.</p><p>Published online 23 Jul 2008</p><p>PMCID:PMC2515321.</p><p></p

CHEK2*1100delC homozygosity in the Netherlands--prevalence and risk of breast and lung cancer

Item does not contain fulltextThe 1100delC mutation in the CHEK2 gene has a carrier frequency of up to 1.5% in individuals from North-West Europe. Women heterozygous for 1100delC have an increased breast cancer risk (odds ratio 2.7). To explore the prevalence and clinical consequences of 1100delC homozygosity in the Netherlands, we genotyped a sporadic breast cancer hospital-based cohort, a group of non-BRCA1/2 breast cancer families, and breast tumors from a tumor tissue bank. Three 1100delC homozygous patients were found in the cohort of 1434 sporadic breast cancer patients, suggesting an increased breast cancer risk for 1100delC homozygotes (odds ratio 3.4, 95% confidence interval 0.4-32.6, P=0.3). Another 1100delC homozygote was found in 592 individuals from 108 non-BRCA1/2 breast cancer families, and two more were found after testing 1706 breast tumors and confirming homozygosity on their wild-type DNA. Follow-up data was available for five homozygous patients, and remarkably, three of them had developed contralateral breast cancer. A possible relationship between 1100delC and lung cancer risk was investigated in 457 unrelated lung cancer patients but could not be confirmed. Due to the small number of 1100delC homozygotes identified, the breast cancer risk estimate associated with this genotype had limited accuracy but is probably higher than the risk in heterozygous females. Screening for CHEK2 1100delC could be beneficial in countries with a relatively high allele frequency