Pooling data from numerous studies has helped scientists examine specific genetic variants related to breast cancer incidence, according to a study in the October 4 issue of the Journal of the National Cancer Institute.
The Breast Cancer Association Consortium brought together data from more than 20 groups conducting breast cancer research. Numerous studies by the collaboration's groups have identified a number of single nucleotide polymorphisms' single variations in a gene, known as SNPs, that may be linked to breast cancer.
The collaborating groups identified 16 SNPs that had been analyzed by at least three of their studies. They pooled data from all studies for each SNP and assessed how frequently the genetic change occurred in breast cancer patients compared to controls.
The authors found that five of the SNPs might be linked to breast cancer risk (with borderline statistical significance) and 11 were not. They suggest that pooling data from many groups can enable large sample sizes necessary to see associations when effects are moderate.
"This study illustrates the value of large consortia for clarifying risks associated with complex diseases," the authors write.
In an accompanying editorial, John P.A. Ioannidis, M.D., of the University of Ioannina School of Medicine in Greece, calls the study an "impressive collaborative effort." He discusses the difficulty of designing studies to accurately assess the significance of rare genetic changes. He writes, "If common genetic variants modulate susceptibility to common diseases such as breast cancer, we now have excellent tools to dissect them."
Article: The Breast Cancer Association Consortium. Commonly studied single-nucleotide polymorphisms and breast cancer: results from the Breast Cancer Association Consortium. J Natl Cancer Inst 2006; 98:1382-1396.
Editorial: Ioannidis JPA. Common genetic variants for breast cancer: 32 largely refuted candidates and larger prospects. J Natl Cancer Inst 2006;98:1350-1353.
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.