1. ¹Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
2. ²Department of Pathology, University of California San Francisco, San Francisco, CA, USA
3. ³Cancer Center and Department of Laboratory Medicine and Urology, University of California San Francisco, San Francisco, CA, USA
4. ⁴Department of Surgery, University of California San Francisco, San Francisco, CA, USA

Correspondence: Dr ES Hwang, MD, UCSF Cancer Center, 1600 Divisadero Ave., B606, San Francisco, CA 94115, USA. E-mail: shelley.hwang@ucsfmedctr.org

Received 26 July 2004; Revised 29 September 2004; Accepted 29 September 2004; Published online 14 January 2005.

Abstract

Array-based comparative genomic hybridization (CGH) is a technique that allows genome wide screening of gains and losses in DNA copy number. In cases where multiple tumors are encountered, this genetic technique may prove useful in differentiating new primary tumors from recurrences. In this case report, we used array-based CGH to examine the genomic relationships among two leiomyosarcomas and two breast cancers in the same patient, three of which were diagnosed synchronously. Array-based CGH was performed on the four tumor samples using random prime amplified microdissected DNA. Samples were hybridized onto bacterial artificial chromosome arrays composed of approximately 2400 clones. Patterns of alterations within the tumors were compared and genetic alterations among the leiomyosarcomas and breast lesions were found. Overall, three distinct genetic profiles were observed. While the two leiomyosarcomas shared a similar pattern of genetic alterations, the two invasive breast lesions did not. The nearly identical pattern of genetic alterations belonging to the two metachronous leiomyosarcomas confirmed metastatic recurrence while the two different genetic profiles of the invasive ductal carcinomas suggest that the two lesions represented two distinct foci of multifocal disease rather than clonal extension of the primary tumor. We conclude that genetic analysis by array-based CGH can clearly elucidate the relationships between multiple tumors and may potentially serve as an important clinical tool.