Citation of original article:

van der Hout AH, et al. A DGGE system for comprehensive mutation screening of BRCA1 and BRCA2: application in a Dutch cancer clinic setting. Human Mutat 2006; 27(7): 654–666.

Abstract of the original article:

Rapid and reliable identification of deleterious changes in the breast cancer genes BRCA1 and BRCA2 has become one of the major issues in most DNA services laboratories. To rapidly detect all possible changes within the coding and splice site determining sequences of the breast cancer genes, we established a semiautomated denaturing gradient gel electrophoresis (DGGE) mutation scanning system. All exons of both genes are covered by the DGGE scan, comprising 120 amplicons. We use a semiautomated approach, amplifying all individual amplicons with the same PCR program, after which the amplicons are pooled. DGGE is performed using three slightly different gel conditions. Validation was performed using DNA samples with known sequence variants in 107 of the 120 amplicons; all variants were detected. This DGGE mutation scanning, in combination with a PCR test for two Dutch founder deletions in BRCA1 was then applied in 431 families in which 52 deleterious changes and 70 unclassified variants were found. Fifteen unclassified variants were not reported before. The system was easily adopted by five other laboratories, where in another 3593 families both exons 11 were analysed by the protein truncation test (PTT ) and the remaining exons by DGGE. In total, a deleterious change (nonsense, frameshift, splice-site mutation or large deletion) was found in 661 families (16.4%), 462 in BRCA1 (11.5%), 197 in BRCA2 (4.9%), and in two index cases a deleterious change in both BRCA1 and BRCA2 was identified. Eleven deleterious changes in BRCA1 and 36 in BRCA2 had not been reported before. In conclusion, this DGGE mutation screening method for BRCA1 and BRCA2 is proven to be highly sensitive and is easy to adopt, which makes screening of large numbers of patients feasible. The results of screening of BRCA1 and BRCA2 in more than 4000 families present a valuable overview of mutations in the Dutch population.

Since clinical trials have demonstrated that breast conservation is safe and effective for treatment of invasive breast cancer, there has been considerable disagreement and controversy about what constitutes an acceptable margin in breast cancer. Dogmatic adherence to a set margin for all patients may cause a higher mastectomy rate than necessary, and thus it is important to understand how various clinical and pathologic factors affect local recurrence and outcome. This review discusses that controversy, as well as what factors should be considered when evaluating patients on an individual basis.