c-erbB2/neu gene and chromosome 17 analysis in breast cancer by FISH on archival cytological fine-needle aspirates

Abstract

Fine-needle aspiration (FNA) is a well-established method for diagnosing breast cancer which has recently been successfully combined with molecular and cytogenetic analysis (Ljung et al, 1994). c-erbB2/neu overexpression is usually detected by the immunocytochemical (ICC) technique, although the methodological and specimen variability, and differences in antibody sensitivity, make this technique not entirely reproducible and, therefore, not highly reliable (Troncone et al, 1993;Corkill et al, 1994;Press et al, 1994;Midulla et al, 1995). On the other hand, the quantification of c-erbB2/neu copy number with semi-quantitative polymerase chain reaction (PCR) (Lonn et al., 1996) does not allow the performance of a 'cell by cell' analysis and the evaluation of gene distribution. The feasibility of dual-colour fluorescence in situ hybridization (FISH) on cytological material from FNA (performed on thawed tissue samples using a 24-gauge needle) has already been described (Sauter et al, 1996). Similarly, one-colour FISH on archival cytological samples up to 94 days old has been successfully performed (Cajulis et al, 1996). We have recently started to perform FNA for TP53 molecular analysis in a number of patients candidate to primary chemotherapy for breast cancer (Lavarino et al, 1998). In this paper, we further developed a cytogenetic approach applying dual-colour FISH analysis of c-erbB2/neu (Kallionemi et al, 1992) to material obtained from the same pass from the same patient series and to a new series.c-erbB2/neu, which is located on chromosome 17q11.2-q12 and chromosome 17 pericentromeric probes, were co-hybridized on fresh cytological smears and, when the latter were not available, on destained smears. A number of cases, of which fresh frozen material was available, were also analysed for c-erbB2/neu overexpression by means of conventional ICC technique. The purposes of this analysis were as follows: (i) to verify the feasibility of a molecular-cytogenetic analysis for c-erbB2/neu gene amplification on FNA material, (ii) to verify the possibility of using frozen and/or destained smears, and (iii) to compare molecular-cytogenetic and ICC results. The results show that dual-colour FISH may be successfully performed on each type of smear. The quantification and evaluation of spatial distribution and the heterogeneity level of c-erbB2/neu amplification among the nuclei represent an obvious advantage of FISH over ICC. Moreover, the higher sensitivity and reproducibility, as well as the evaluation of the chromosome copy number, make FISH unique for the assessment of c-erbB2/neu gene amplification on FNA material. MATERIALS AND METHODS Patients and tumoursFifty-eight consecutive female patients (age range 25-71 years; mean 53 years) with primary breast carcinoma ascertained by FNA, who had entered a primary chemotherapy protocol with doxorubicin and paclitaxel, were selected for the present study. According to the tumour node and metastasis classification (TNM; UICC, 1992), one case was T4bN2M1, one case T4bN2M0, three c...

PTEN losses exhibit heterogeneity in multifocal prostatic adenocarcinoma and are associated with higher Gleason grade

“…As with the TMPRSS2-ERG FISH described above, this approach was particularly useful for cores exhibiting more cellular heterogeneity where cells differed in shape, size or density. Homozygous deletion status for PTEN was defined by more conservative criteria, a simultaneous lack of both PTEN locus signals 55,[57][58][59] in 430% of scored nuclei. 58 In addition, TMA cores with inconclusive results or high degree of heterogeneity were reevaluated/ rescored using a whole formalin-fixed paraffinembedded section from the original donor block.…”

Current Perspectives on HER2 Testing: A Review of National Testing Guidelines

“…At the moment, surgically excised samples from lumpectomies or mastectomies are preferred, although if these are not available core biopsies can be used. Cell blocks from fine needle aspiration biopsy (FNAB) may also be useful, particularly in the metastatic setting (36,37).…”

Strong Correlation between Results of Fluorescent In Situ Hybridization and Immunohistochemistry for the Assessment of the ERBB2 (HER-2/neu) Gene Status in Breast Carcinoma

“…Indeed, results of molecular methods may be affected by the dilution of tumor material by normal cells and by the determination of the threshold defining the existence of an amplification or an overexpression (2,7,21). Recent technical developments have made possible the detection of the ERBB2 gene in tissue sections, touch preparations, and fine-needle aspirates using fluorescent in situ hybridization (FISH) (16,(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32). The most reliable method to routinely evaluate the status of ERBB2 in prospective and archival material remains to be determined.…”