Loss of BRCA1 and BRCA2 in Breast Tumors
Author Information
Author(s): Staff S, Isola J J, Johannsson O, Borg Å, Tanner M M
Primary Institution: Laboratory of Cancer Genetics, Institute of Medical Technology, University Hospital of Tampere
Hypothesis
The study investigates the somatic loss of BRCA1 and BRCA2 in breast tumors from mutation carriers.
Conclusion
The study found a high prevalence of allelic imbalance at BRCA1 in BRCA2 mutation tumors and vice versa, indicating complex mechanisms in cancer development.
Supporting Evidence
- 73% of informative BRCA1 mutation tumors showed allelic imbalance at the BRCA2 locus.
- 53% of these tumors showed a copy number loss of the BRCA2 gene by FISH.
- 83% of informative BRCA2 mutation tumors showed allelic imbalance at the BRCA1 locus.
- Half of the tumors showed a physical deletion of the BRCA1 gene by FISH.
- 71% of informative hereditary tumors had combined allelic loss of both BRCA1 and BRCA2.
- Only 29% of sporadic control tumors showed copy number losses of both BRCA genes.
Takeaway
The study shows that when one breast cancer gene is mutated, the other gene often has problems too, which can make cancer more likely.
Methodology
The study used allelic imbalance and fluorescence in situ hybridization (FISH) analyses on breast tumors.
Participant Demographics
The study included breast tumors from germ-line BRCA1 and BRCA2 mutation carriers and sporadic cases.
Digital Object Identifier (DOI)
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