[328] Comparison of Breast Cancers in Hispanic and Non-Hispanic Caucasian Women Using Array Comparative Genomic Hybridization

I Yeh, K Beedupalli, T Lu, SR Gunn, RS Robetorye. University of Texas Health Science Center at San Antonio, San Antonio, TX; Combimatrix Molecular Diagnostics, Irvine, CA

Background: In large population studies, Hispanic women are more likely to be diagnosed with higher stage breast cancer and have decreased survival as compared with non-Hispanic Caucasian women. Hypothesized reasons for these discrepancies include biological, socio-economic, environmental and lifestyle variations. Biological differences include hormone receptor status, histological types, and genetic changes. We undertook this analysis to compare breast tumor characteristics at the genomic level in Hispanic and non-Hispanic Caucasian women.
Design: We performed array comparative genomic hybridization on 82 fresh frozen breast carcinomas using an array consisting of over 1100 non-overlapping bacterial artificial chromosome clones. These samples included 54 cases obtained from Hispanic women and 28 cases obtained from non-Hispanic Caucasian women. Genomic gains and losses were determined for each chromosome and the two groups were compared using Fisher's exact test (two tailed).
Results: Common copy number changes in the breast cancers included gains of 1q, 8q, 11q, 12p, 16p, 17q, and 20q, and losses of 5q, 8p, 13q, 16q, and 17p. Comparison of the Hispanic to the non-Hispanic Caucasian cancers showed that only gain of 17q was statistically significant (P= 0.0426).
Conclusions: 17q gain was significantly more common in breast tumors from Hispanic women as compared with non-Hispanic Caucasian women. This chromosomal region includes the HER2 gene, which was more frequently amplified in the Hispanic group. This finding is may be part of the biological etiology of the previously reported poorer prognosis of Hispanic patients with breast cancer.
Category: Breast

Monday, March 9, 2009 1:00 PM

Poster Session II # 33, Monday Afternoon