title: Cytogenetic and comparative genomic hybridization findings in four cases of breast cancer after neoadjuvant chemotherapy.
abstract: To assess a potential common pattern of genetic alterations in chemotherapy-resistant tumors we analyzed four tumors from breast cancer patients (patients 1-4) after neoadjuvant chemotherapy, by comparative genome hybridization (CGH) and conventional chromosome banding analysis. All patients showed structural aberrations involving chromosomes 1, 5, 11, 16, and 17. In CGH analysis, the patients showed typical imbalances for ductal breast cancer: gains of 1q (3 patients), 5q (2 patients), 8q (3 patients), and X (4 patients) and losses of 1p33 approximately p36 (3 patients), 16q (3 patients), 17p (3 patients), 19 (4 patients), and 22q (4 patients). Other recurrent imbalances of atypical pattern for ductal breast cancer were gain of 4q21 approximately q32 (2 patients), 20q21 approximately q22 (2 patients), and 21 (2 patients) and loss of 20p (3 patients). Three patients showed involvement of several regions bearing genes of drug resistance (MDR1 [HUGO symbol: ABCB1], BCRP [HUGO symbol: ABCG2], MRP1 [HUGO symbol: ABCC1], RFC1); the fourth patient displayed an amplification in the region of MYC (alias c-myc), thus providing--at the level of the light microscope--an explanatory background for the ability of their tumors to survive anthracycline-, taxane- and cyclophosphamide-based chemotherapy. Conventional cytogenetic analysis and CGH displayed highly coincidental findings in the tumors of four patients after neoadjuvant chemotherapy for breast cancer.
authors.affiliation: Clinical Division of Oncology, Department of Medicine I, University Hospital Vienna, Vienna, Austria. barbara.doerner@chello.at
authors.forename: Barbara
authors.initials: B
authors.lastname: Fazeny-Dörner
authors.forename: Maria
authors.initials: M
authors.lastname: Piribauer
authors.forename: Catharina
authors.initials: C
authors.lastname: Wenzel
authors.forename: Negar
authors.initials: N
authors.lastname: Fakhrai
authors.forename: Christine
authors.initials: C
authors.lastname: Pirker
authors.forename: Walter
authors.initials: W
authors.lastname: Berger
authors.forename: Roland
authors.initials: R
authors.lastname: Sedivy
authors.forename: Margarethe
authors.initials: M
authors.lastname: Rudas
authors.forename: Martin
authors.initials: M
authors.lastname: Filipits
authors.forename: Ichi
authors.initials: I
authors.lastname: Okamoto
authors.forename: Christine
authors.initials: C
authors.lastname: Marosi
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D002869:Chromosome Aberrations; D005260:Female; D015894:Genome, Human; D006801:Humans; D007621:Karyotyping; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009693:Nucleic Acid Hybridization
chemical_list: D000970:Antineoplastic Agents