Sheila N.J. Sait

Delay to formalin fixation effect on breast biomarkers.

Delay to formalin fixation may invalidate hormone receptors and HER2 analyses. Invalid results of tumor markers could significantly alter the type of adjuvant therapy a patient receives and potentially impact outcome. The purpose of this study was to determine the effects of progressive delay to formalin fixation on breast cancer biomarkers. Ten palpable invasive breast cancers were resected and underwent immediate gross evaluation. For each case, the procured tumor was divided into eight parts and consecutively fixed after 0, 10, 30 min, 1, 2, 4, and 8 h; one section was kept in saline and stored overnight at 4°C. Two tissue microarray blocks were constructed. Estrogen and progesterone receptors and HER2 immunohistochemistry and fluorescence in situ hybridization were carried out. Statistical analyses including non-parametric sign test, exact McNemars test and Pages L test were used. All 10 cases were invasive ductal carcinomas. Q score ⩾6 was identified in five cases for estrogen receptor and four for progesterone receptor. Mean Q score started to decline at the 2 h mark for estrogen receptor and 1 h mark for progesterone receptor. Lowest score was at 8 h mark for estrogen receptor and overnight for progesterone receptor. HER2 fluorescence in situ hybridization started to be compromised for interpretation at the 1 h mark and became statistically significant at the 2 h mark (P<0.03). To avoid delay to formalin fixation as a factor negatively affecting on breast biomarkers, we recommend not to delay formalin fixation for more than 1 h and not to store specimens overnight.

Double minute chromosomes in acute myeloid leukemia and myelodysplastic syndrome: Identification of new amplification regions by fluorescence in situ hybridization and spectral karyotyping

Double minute chromosomes (dmin) are small chromatin bodies consisting of genes amplified in an extrachromosomal location. dmins are uncommon in hematologic malignancies; they are seen primarily in acute myeloid leukemia, with amplification of the MYC oncogene or, less frequently, the MLL transcription factor. Nine patients with hematologic malignancies with dmin were seen at the Roswell Park Cancer Institute between 1985 and 2000; eight had acute myeloid leukemia and one a myelodysplastic syndrome. Fluorescence in situ hybridization (FISH) demonstrated MYC amplification on dmin in four patients, but MLL amplification was not seen. Spectral karyotyping showed that the dmin derived from chromosome 11 in one patient and from chromosome 19 in two others without MYC or MLL amplification; derivation from these chromosomes was confirmed by FISH with chromosome paint probes. The dmin of chromosome 11 origin hybridized to a bacterial artificial chromosome (BAC) RP11‐112M22 that maps to 11q24.3 and is predicted to contain ETS1 and other markers, including D11S11351 and D11S4091. The dmin of chromosome 19 origin in one patient hybridized to BACs RP11‐46I12 and RP11‐110J19; in the other patient, these clones did not hybridize with the dmin, but were found to be amplified on a marker chromosome that was derived from chromosome 19 in that patients cells. These BACs have been mapped to 19q12–19q13.1 and 19q11–19q13.1, respectively, and are predicted to contain the markers D19S409 and D19S919 and the gene for ubiquinol‐cytochrome C reductase, Rieske iron‐sulfur polypeptide1 (UQCRFS1). dmin originating from chromosome 19 have not been reported previously in hematologic malignancies.

HER-2/neu Protein Expression and Gene Alteration in Stage I-IIIA Non-Small-Cell Lung Cancer: A Study of 140 Cases Using a Combination of High Throughput Tissue Microarray, Immunohistochemistry, and Fluorescent In Situ Hybridization

Regarding HER-2/ neu expression (gene or protein level) in lung cancer, several studies with inconsistent results have been recently reported, partially due to variable techniques used and/or heterogeneous populations examined. The objective of this study was to examine HER-2/ neu expression in a well-defined cohort of non–small-cell lung cancers (NSCLC) and in nonneoplastic lung tissue utilizing a combination of high-density tissue microarray, immunohistochemistry (IHC), and fluorescent in situ hybridization (FISH) under uniform test conditions. One hundred forty stage I-IIIA primary NSCLCs and 38 non-neoplastic lung samples were examined. IHC, using an FDA-approved Hercept monoclonal antibody kit, was performed and HER-2/ neu gene alteration was assessed by FISH. The association of expression of HER-2/ neu with clinicopathologic parameters was analyzed. Ninety-four percent of tumor samples (131/140) were fully interpretable after tissue processing. Twenty-five of them (19%) overexpressed (2+, 3+) HER-2/ neu, while 106 (81%) had no or weak expression. All thirty-four interpretable non-neoplastic lung samples were negative for HER-2/ neu alteration at protein and gene level. HER-2/ neu protein overexpression correlated well with HER-2/ neu gene amplification (r =.83, P < 0.001). HER-2/ neu overexpression was significantly associated with histologic subtype: 19 adenocarcinomas (19/82, 23%) versus 4 squamous cell carcinomas (4/44, 9%) overexpressed Her-2/ neu (P = 0.04). Statistical significance was observed between HER-2/ neu expression and tumor differentiation, with strong positive (3+) expression observed more frequently in poorly differentiated tumors (P = 0.01). Patients with HER-2/ neu abnormalities, particularly HER-2/ neu gene amplification, exhibited a shorter survival (P = 0.043). The statistically significant difference (P < 0.005) between HER-2/ neu alteration in tumor samples(25/131, 19%) and in the nonneoplastic tissue (0/34, 0%) implies that HER-2/ neu may have a role in the carcinogenesis of NSCLC. The findings provide evidence supporting the hypothesis that the HER-2/ neu receptor may represent a useful molecular target in the treatment of NSCLC. The significant association of HER-2/ neu expression and gene amplification with poorly differentiated carcinoma compared with well differentiated carcinoma suggests that HER-2/ neu may be involved in NSCLC tumor evolution. Patients with HER-2/ neu gene amplification and strong positive expression of HER-2/ neu protein showed a strong tendency toward shorter survival.

Diagnostic utility of FLI-1 monoclonal antibody and dual-colour, break-apart probe fluorescence in situ (FISH) analysis in Ewing's sarcoma/primitive neuroectodermal tumour (EWS/PNET). A comparative study with CD99 and FLI-1 polyclonal antibodies.

Aims:  To compare the sensitivity and specificity of the recently commercially available FLI‐1 monoclonal (FLI‐1m) antibody with the currently used antibodies [CD99 and FLI‐1 polyclonal (FLI‐1p)] in the diagnosis of Ewings sarcoma/primitive neuroectodermal tumour (EWS/PNET) and to determine the diagnostic value of the EWSR1 (22q12) dual‐colour, break‐apart rearrangement probe fluorescence in situ hybridization (FISH) technique.

Trisomy 4: An entity within acute nonlymphocytic leukemia☆

Trisomy 4 is a newly recognized primary chromosome change in leukemia. Five cases of acute nonlymphocytic leukemia (ANLL) are described from the United States and France. As in cases from Belgium, the only chromosome abnormality detected in the leukemic cells was trisomy 4. This was associated preferentially with ANLL of the M4 type (by FAB classification): acute myelomonocytic leukemia.

Immunoreactivity of MIC2 (CD99) in Acute Myelogenous Leukemia and Related Diseases

MIC2 is characteristically expressed in lymphoblastic lesions and Ewing’s/primitive neuroectodermal tumor sarcomas. Although MIC2 has recently been reported in chloroma and rare terminal deoxynucleotidyl transferase–positive acute myelogenous leukemia (AML), the incidence and the significance of MIC2 (CD99) immunoreactivity in myeloid lesions is not clear. In this study, we evaluated MIC2 positivity in a variety of myeloid diseases and normal marrow to determine its incidence and distribution in myeloid diseases; its correlation with flow cytometric and cytogenetic data in AML; and its association with leukemic transformation, relapse, and chloroma formation. Paraffin sections of 11 chloromas and 94 bone marrow core biopsies from 66 patients were stained with CD99 monoclonal antibody 12E7. Of 94 bone marrow core biopsies, there were 30 AML (fragment antigen binding M0 to M6), 23 remissions, 5 relapses, 12 myeloproliferative disorders, 13 myelodysplastic syndromes, and 11 normal marrows from patients who did not have leukemia. CD99 immunoreactivity was evaluated with light microscopy. MIC2 expression was seen in leukemic blasts in 6 of 11 chloromas (55%) and 13 of 30 AML (43%) but rarely in myeloproliferative disorders, myelodysplastic syndromes, remission, and normal marrow. CD99 tended to be positive in M1-, M3-, and HLA-Dr–negative AML and negative in AML with relapse. MIC2 expression did not correlate with the karyotype independent of French-American-British Cooperative Group classification and the disease remission or occurrence of chloroma in AML. We concluded that MIC2 is commonly expressed in leukemic blasts of AML and is not predictive of leukemic transformation from myeloproliferative disorders and myelodysplastic syndromes or chloroma formation. Caution should be taken when using MIC2 as a marker for Ewing’s sarcoma/primitive neuroectodermal tumor or lymphoblastic lymphoma on paraffin sections of either soft tissue or bone marrow specimens.

Tetrasomy of chromosome 8: An interesting and rare cytogenetic phenomenon in acute nonlymphocytic leukemia

Trisomy of chromosome #8 is a change commonly associated with acute nonlymphocytic leukemia (ANLL). However, tetrasomy of chromosome #8 in ANLL as a single chromosome change without accompanying abnormalities is extremely rare and, to the best of our knowledge, has not been reported to date. We present here a case of acute monocytic leukemia (AMoL, FAB M5b) with four copies of chromosome #8.

Hypoxia-inducible factor-1α protein expression is associated with poor survival in normal karyotype adult acute myeloid leukemia

We examined the predictive impact of HIF-1α protein expression on clinical outcome of 84 normal karyotype acute myeloid leukemia (NK-AML) patients (median age 66.5 years) at our institute. Thirty percent of NK-AML cells expressed cytoplasmic HIF-1α. In univariate analysis, low HIF-1α (≤ 5%, n = 66) was associated with improved event-free survival (p = 0.0453, HR = 0.22). Multivariate analysis incorporating age, complete remission, FLT3-ITD mutation, and marrow blast percentage demonstrated that HIF-1α was independently associated with poorer overall and event-free survival. HIF-1α expression correlated with VEGF-C but not VEGF-A, marrow angiogenesis, FLT3 ITD or NPM1 mutations. These results support HIF-1α as an outcome marker for NK-AML.

Truncated STAT proteins are prevalent at relapse of acute myeloid leukemia

Signal transducer and activator of transcription (STAT) proteins are implicated in the control of cell survival, proliferation and differentiation in response to hematopoietic cytokines. C-terminally truncated STAT isoforms (STATbeta), as opposed to the full length form (STATalpha), have a competitive or even transdominant negative effect on gene induction mediated by the STAT pathway. We have previously demonstrated that while constitutively active STAT proteins were detected in ten of 36 (28%) for STAT3 and eight of 36 (22%) for STAT5 in pretreatment samples from newly diagnosed acute myeloid leukemia (AML) patients, a significantly larger fraction of samples [21 of 27 (78%)] expressed STATbeta proteins. To determine whether STATbeta expression was maintained or increased after relapse in AML, we compared STAT activity and isoform expression at diagnosis and at relapse in 17 patients. In this selected group, constitutively active STAT3 was detected in 13 of 17 (76%) AML samples at diagnosis but was detected in only four of these patients at relapse. Constitutively active STAT5 was detected in three of 17 (18%) AML samples at diagnosis; but only two at relapse. In contrast, STATbeta protein expression was observed in 12 of the 17 pretreatment samples (71%) and in 16 of 17 samples at relapse. Only one patient did not express STATbeta at relapse. Our results suggest that STATbeta isoform expression, rather than level of constitutive activity, may be involved in disease progression in AML.

Demonstration of Urokinase Expression in Cancer Cells of Colon Adenocarcinomas by Immunohistochemistry and in Situ Hybridization

The question whether urokinase is expressed in human colon cancer by the cancer cells themselves or by surrounding stromal elements such as fibroblasts, macrophages, and leukocytes, which transfer the activator to the receptors of the cancer cells, has been a controversial one. In the present study 12 cases of colorectal cancer were investigated by immunohistochemical methods using three monoclonal antibodies of different specificity against urokinase. Cytoplasmic staining of strongly varying intensity was observed in all cases, with the antigen expressed most strongly in the apical and the basal regions of the cancer cells. In some cases, staining was also found in stromal elements surrounding the cancer glands. That the activator was indeed the product of the cancer cells was demonstrated by in situ hybridization using a uPA-cDNA probe, which detected the presence of uPA-mRNA in both the basal and the apical regions of the cancer cells. A monoclonal antibody against the receptor for uPA showed similar localization. These findings indicate that the activator is expressed by the cancer cells and is not recruited by them from stromal elements.