MOLECULAR-GENETIC ANALYSIS OF EASILY ACCESSIBLE BREAST-TUMOR DNA, PURIFIED FROM TISSUE LEFT OVER FROM HORMONE-RECEPTOR MEASUREMENT

In order to establish a large panel of normal and tumour DNA from prim ary breast cancer patients, we looked for a source of easily accessibl e, good quality breast tumour DNA. Following routine hormone receptor analysis at the hospital the leftover pellets contained the nuclei fro m the tumour tissue. We collected 670 pellets over a period of 2 1/4 y ears and isolated a large amount of DNA (on average 400 mu g per pelle t). To control the quality of this tumour DNA, we analysed 41 pellets and matching normal DNA for loss of heterozygosity (LOH), with 11 micr osatellite markers along chromosome 17. This chromosome is well descri bed for boast cancer. LOH is a sensitive method, requiring good qualit y and pure tumour DNA. Contamination with normal DNA will blur the res ults. We found a high rate of LOH, ranging from 33 to 74%, which is in agreement with other reports, and therefore recommend this rich sourc e of breast tumour DNA for molecular biological analysis.