Molecular cytogenetics of primary breast cancer by CGH

✍ Scribed by Mika Tirkkonen; Minna Tanner; Ritva Karhu; Anne Kallioniemi; Jorma Isola; Olli-P. Kallioniemi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 94 KB
• Volume: 21
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/(sici)1098-2264(199803)21:3<177::aid-gcc1>3.0.co;2-x

✦ Synopsis

Comparative genomic hybridization (CGH) reveals DNA sequence copy number changes that are shared among the different cell subpopulations present in a tumor and may help to delineate the average progression pathways of breast cancer. Previous CGH studies of breast cancer have concentrated on selected subgroups of breast cancer. Here, 55 unselected primary breast carcinomas were analyzed using optimized quality-controlled CGH procedures. Gains of 1q (67%) and 8q (49%) were the most frequent aberrations. Other recurrent gains were found at 33 chromosomal regions, with 16p, 5p12-14, 19q, 11q13-14, 17q12, 17q22-24, 19p, and 20q13 being most often (Ͼ18%) involved. Losses found in Ͼ18% of the tumors involved 8p, 16q, 13q, 17p, 9p, Xq, 6q, 11q, and 18q. The total number of aberrations per tumor was highest in poorly differentiated (P ϭ 0.01) and in DNA aneuploid (P ϭ 0.05) tumors. The high frequency of 1q gains and presence of ϩ1q as the sole abnormality suggest that it is an early genetic event. In contrast, gains of 8q were most common in genetically and phenotypically advanced breast cancers. The vast majority of breast cancers (80%) have gains of 1q, 8q, or both, and 3 changes (ϩ1q, ϩ8q, or Ϫ13q) account for 91% of the tumors. In conclusion, CGH results indicate that certain chromosomal imbalances are very often selected for, sometimes in a preferential order, during the progression of breast cancer. Further studies of such common changes may form the basis for a molecular cytogenetic classification of breast cancer.