Distinctive genomic alterations seen in sporadic early onset breast cancer

Sporadic early onset breast cancer is characterized by specific chromosome aberrations that may be to blame for the reduced survival of these patients, researchers from Germany report.

“Sporadic breast cancer in young women is different from the one in older patients regarding pathological features and aggressiveness of the tumors, but the spectrum of genetic alterations is largely unknown,” Dr. Anna Jauch from University of Heidelberg and colleagues write in the November 20th International Journal of Cancer. To investigate, they used comparative genomic hybridization (CGH) to analyze DNA copy number changes in 88 primary breast carcinomas obtained from women age 35 or younger. They correlated specific genetic alterations with a number of pathological features including tumor type, grade, lymph node status, and distant metastases. “In our CGH study of young woman with breast cancer, we found a similar spectrum of genomic imbalances as has been described in breast cancer in general,” Dr. Jauch told Reuters Health.”However, chromosomal gains were more frequent than losses compared to published data,” she said. Genomic gains clustered to chromosome arms 1q (64.8%), 8q (61.4%), 17q (50.0%), 20q (33.0%), 3q (20.5%), and 1p, 5p, and 15q (17% for each). Genomic losses occurred commonly on 8p (19.3%), 11q, 16q, and 17p (11.4% for each), and 18q (10.2%). “As in older women with breast cancer, gains to chromosome arms 8q were associated with a higher tumor grade,” Dr. Jauch said, “and amplification of the c-myc oncogene region (8q24) was correlated with aggressive tumor type, high histological grade, poor distant metastasis free-survival and lymph node metastasis.” “Deletions of 8p22-p23 showed a significant correlation with a positive lymph node metastasis indicating a poor prognosis,” the researcher further reported. The data suggest that genomic imbalances in early-onset breast tumors often affect distinct chromosomal subregions that harbor well-known or putative tumor-relevant genes. These results suggest a possible reason behind the reduced survival seen in young women with breast cancer compared with their older counterparts, the researchers conclude. (Source: Int J Cancer 2003;107:583-592: Reuters Health: Megan Rauscher: December 24, 2003: Oncolink)