Molecular genetic investigations of breast carcinoma

Konference: 2009 5. sympózium a workshop molekulární patologie a histo-cyto-chemie

Kategorie: Nádorová biologie/imunologie/genetika a buněčná terapie

Téma: Postery

Číslo abstraktu: p015

Autoři: Mgr. Irena Urbanovská; Mgr. Barbora Kubová; R. Skalíková; RNDr. Magdalena Uvírová; Doc.MUDr. Jana Dvořáčková, Ph.D., M.I.A.C

Aims: Breast cancer is a heterogeneous disease resulting from the acquisition of probably multiple static mutations which, in combination, define the characteristics of the tumour. Methods of molecular genetics have become an essential part of diagnostic and prognostic methods in oncology of solid tumours. Trastuzumab (Herceptin) is the cornerstone of molecular biology treatment of breast cancer women with HER2/NEU gene amplification. Accurate assessment of HER2/NEU status is therefore critical for identifying patients who may benefit from trastuzumab-based therapy. HER2/NEU gene amplification and overexpression were evaluated by IHC and FISH.

Methods: Breast carcinomas were investigated by imuno-histochemistry (IHC), fluorescence in situ hybridisation (FISH) and comparative genomic hybridisation (CGH).

Results: IHC was performed with DAKO Cytomation HercepTest and FISH with PathVysion Probe Kit. A total of 213 (10,56%) of 2017 patients were positive by IHC. These positive IHC results (2+, 3+) were verified by FISH. HER2/NEU gene amplification was confirmed in 138 cases (70%). CGH was performed at 29 cases to screen breast tumors for copy number changes. We obtained successful results in 26 of 29 cases. 22 cases were positive for copy number changes, 4 cases were negative for copy number changes probably due to analysis of non tumour tissue. The most frequent DNA sequence copy number changes were gains of 1q (14 cases), 8q (13 cases) and loss of 1p (14 cases), 16q (12 cases).

Conclusions: Our results indicate that especially borderline results of IHC (2+) should be interpreted with caution using both IHC and FISH with standardised metodology. The prevalence of the most common copy number aberrations detected by CGH was roughly similar to that reported in the literature.

Datum přednesení příspěvku: 24. 4. 2009