Biomedical subjects

Jorma Isola

Publications and source records attributed to Jorma Isola.

50 records · Page 3Linked to original sources

PubMed2003

Characterization of a novel breast carcinoma xenograft and cell line derived from a BRCA1 germ-line mutation carrier.

A human tumor xenograft (L56Br-X1) was established from a breast cancer axillary lymph node metastasis of a 53-year-old woman with a BRCA1 germ-line nonsense mutation (1806C>T; Q563X), and a cell line (L56Br-C1) was subsequently derived from the xenograft. The xenograft carries only the mutant BRCA1 allele and expresses mutant BRCA1 mRNA but no BRCA1 protein as determined by immunoprecipitation or Western blotting. The primary tumor, lymph node metastasis, and xenograft were hypodiploid by DNA flow cytometry, whereas the cell line displayed an aneuploidy apparently developed via polyploidization. Cytogenetic analysis, spectral karyotyping, and comparative genomic hybridization of the cell line revealed a highly complex karyotype with numerous unbalanced translocations. The xenograft and cell line had retained a somatic TP53 missense mutation (S215I) originating from the primary tumors, as well as a lack of immunohistochemically detectable expression of steroid hormone receptors, epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER-2), and keratin 8. Global gene expression analysis by cDNA microarrays supported a correlation between the expression profiles of the primary tumor, lymph node metastasis, xenograft, and cell line. We conclude that L56Br-X1 and L56Br-C1 are useful model systems for studies of the pathogenesis and new therapeutic modalities of BRCA1-induced human breast cancer.

Aneuploidy↗

PubMed2003

Current perspectives on HER2 testing: a review of national testing guidelines.

Knowledge of HER2 status is a prerequisite when considering a patient's eligibility for Herceptin (trastuzumab) therapy. Accurate assessment of HER2 status is essential to ensure that all patients who may benefit from Herceptin are correctly identified. There are several assays available to determine HER2 status: the most common in routine clinical practice are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Various factors can affect the results achieved with these assays, including the assay antibody/probe, the methodology and the experience of personnel. Many countries have implemented national testing guidelines in an attempt to standardize testing procedures and make results more accurate. These guidelines vary in the level of detail and the number of recommendations. This review looks at areas of consensus between the different national testing guidelines and highlights where errors may arise during the testing procedure. The key point underlined by this review is that whatever method is used to test for HER2 status, the technology must be validated first, and there must be regular internal and external quality control and quality assurance procedures.

Algorithms↗

PubMed2003

Amplification of erbB2 and erbB2 expression are superior to estrogen receptor status as risk factors for distant recurrence in pT1N0M0 breast cancer: a nationwide population-based study.

PURPOSE: To assess the relative importance of 10 prognostic factors in pT1N0M0 breast cancer (< or =2 cm in diameter, node negative). EXPERIMENTAL DESIGN: Women diagnosed with breast cancer in Finland from 1991 to 1992 were identified from the files of the Finnish Cancer Registry, and individual clinicopathological data were collected from the hospital case records of women living in five regions comprising about one-half of the Finnish population. Of the women with minimum required information available (n = 2842), 852 had unilateral pT(1)N(0)M(0) cancer. The median follow-up time was 9.5 years, and only 5% had received systemic adjuvant therapy. Estrogen receptor (ER), progesterone receptor, erbB2, p53, and Ki-67 expression was determined from tumor tissue microarrays using immunohistochemistry, and the erbB2 (HER-2) amplification status was determined using chromogenic in situ hybridization. RESULTS: Primary tumor size < or =5 mm and histological grade 1 were associated with 100 and 95% (95% confidence interval, 92-98%) 9-year distant disease-free survival, respectively, whereas strong erbB2 expression or the presence of >20% Ki-67-positive cells was associated with >20% risk. ER and progesterone receptor values obtained from the hospital case records or tumor microarrays showed weaker association with outcome than the erbB2 status. Small (< or =10 mm) erbB2-negative cancers were associated with >90% 9-year distant disease-free survival, irrespective of histological grade. CONCLUSIONS: Prognosis of pT(1)N(0)M(0) breast cancer is generally well defined by the histological grade and primary tumor size. The erbB2 status was superior to ER as a prognostic factor in these tumors.

Adult↗

PubMed2003

Topoisomerase II alpha as a marker predicting the efficacy of anthracyclines in breast cancer: are we at the end of the beginning?

This article attempts to provide the reader with a complete overview of topoisomerase (topo) II alpha as a marker for predicting the efficacy of anthracyclines in patients with breast cancer. In the first section of this article, in vitro data supporting the predictive value of topo II alpha are reviewed. Interestingly, these data suggest that the interaction between HER2 and anthracycline efficacy, which has been hypothesized in several clinical studies performed in the past decade, might depend on the concomitant topo II alpha status. Molecular pathology studies further reinforce the concept that HER2 might not be directly involved in the prediction of response to anthracyclines. They report that topo II alpha gene amplification can be found in 25%-40% of HER2/neu-amplified tumors, while no topo II gene amplification is detected in the absence of HER2/neu gene amplification. In the second part of this article, a series of clinical studies are reviewed and interpreted. These studies have attempted to correlate topo II alpha status with anthracycline efficacy in the adjuvant, neoadjuvant, and metastatic settings. All of the studies evaluating the topo II alpha gene suggest that gene amplification might be associated with an increased efficacy of anthracyclines, and some of the studies evaluating topo II alpha protein find that protein overexpression might correlate with an increased sensitivity to these compounds. Despite these findings, however, the reported studies do not provide the proof of principle needed to authorize the use of topo II alpha as a predictive marker for standard practice. A new generation of research is currently testing the predictive value of topo II alpha. It is hoped that these projects, which are described in the last section of the article, will clarify the role of topo IIa in the prediction of response to anthracyclines.

Anthracyclines↗

PubMed2003

Evaluation of a web-based system for survival estimation in breast cancer.

OBJECTIVES: To evaluate the accuracy of an internet-based method for survival estimation in breast cancer. DESIGN: A website was created which allows the user to enter information on prognostic factors for a patient, and instantly obtain a Kaplan-Meler survival curve based on outcome data of prior cases with a matching prognostic factor profile. The source for the survival data is a Finnish nationwide series of 2,842 women diagnosed with breast cancer in 1991-2, comprising 91% of all cases within the selected geographical regions during these two years. MAIN OUTCOME MEASURES: The accuracy of the survival estimates obtained using data from the nationwide series was assessed in an independent, single institution validation series (n = 565), and measured by analysis of calibration and discrimination (the area under the ROC curve). RESULTS: A selection of prognostic factors recommended by the National Institutes of Health (NIH) Consensus Development Panel and the International Consensus Panel on the Treatment of Primary Breast Cancer were made available for case-matching on the website. Kaplan-Meier case-match eight-year estimates of distant disease-free survival (DDFS) based on combinations of tumour size, histologic grade and mode of detection (screen-detected vs. symptomatic) were close to the actual outcomes, e.g. patients in the validation set who were estimated to have a 71-80%, 81-90% and 96-100% DDFS had an actual average DDFS of 76%, 88%, and 100%, respectively. CONCLUSIONS: A web-based case-match system can generate survival curves for user-defined prognostic factor combinations and identify patients with a varying risk for breast cancer recurrence. The system can be linked to other data sets, expanded to accommodate new prognostic factors and used as a source for population-based survival estimates.

Breast Neoplasms↗

PubMed2002

Few FH mutations in sporadic counterparts of tumor types observed in hereditary leiomyomatosis and renal cell cancer families.

Loss of function mutations in the fumarate hydratase (fumarase, FH) gene were recently identified as the cause for dominantly inherited uterine and cutaneous leiomyomas and renal cell cancer. To further evaluate the role of FH in tumorigenesis, we screened FH mutations from tumor types seen in hereditary leiomyomatosis and renal cell cancer mutation carriers-41 uterine and 10 cutaneous leiomyomas, 52 renal cell carcinomas, 53 sarcomas, 29 prostate carcinomas, and 15 lobular breast carcinomas. Few mutations were detected. Biallelic inactivation of FH was found in one uterine leiomyosarcoma, one cutaneous leiomyoma, and one soft tissue sarcoma. Whereas the two former lesions were shown to originate from a germ-line mutation, the soft tissue sarcoma is to our knowledge the first example of purely somatic inactivation of FH in tumors.

Base Sequence↗

PubMed2002

Cancer incidence in families with multiple glioma patients.

Twenty-four Finnish families with 2 or more glioma patients were identified through questionnaires sent to 369 consecutive glioma patients receiving surgery at Tampere University Hospital during 1983-94. To explore whether unusual cancer susceptibility is involved, the cancer risk of 2,664 family members was estimated using population-based data from the Finnish Cancer Registry. Among the total cohort of relatives, 88 cancers were observed during 1953-97. The overall cancer risk among 12 families with juvenile onset gliomas was significantly decreased (standardized incidence ratio [SIR] 0.6, 95% confidence interval [CI]: 0.4-0.9). Among 12 families with adult onset gliomas, the overall cancer risk was equal to that of the reference population (SIR 1.1, 95% CI: 0.8-1.4) whereas the risk of skin melanoma (SIR 4.0, 95% CI: 1.5-8.8) and meningioma (SIR 5.5, 95% CI: 1.1-16) were significantly increased. Several other tumors, including those associated with neurofibromatosis 1 and 2, tuberous sclerosis and Li-Fraumeni and Turcot syndromes were surveyed, but no elevated risks were observed. In conclusion, the presence of meningiomas and skin melanomas in glioma families may indicate a novel association as a cancer susceptibility trait.

Adult↗

PubMed2002

Prognostic significance of elevated cyclooxygenase-2 expression in breast cancer.

Cyclooxygenase-2 (Cox-2) expression can induce mammary tumorigenesis in transgenic mice, and selective Cox-2 inhibitors are both chemopreventive and chemotherapeutic in rat models of breast cancer. We analyzed the expression of Cox-2 protein by immunohistochemistry in tissue array specimens of 1576 invasive breast cancers. Moderate to strong (elevated) expression of Cox-2 protein was observed in 37.4% of the tumors, and it was associated with unfavorable distant disease-free survival (P < 0.0001). Elevated Cox-2 expression was associated with a large tumor size, a high histological grade, a negative hormone receptor status, a high proliferation rate (identified by Ki-67), high p53 expression, and the presence of HER-2 oncogene amplification (P < 0.0001 for all comparisons), along with axillary node metastases and a ductal type of histology (P = 0.0001 and P = 0.0017, respectively). Interestingly, association with the unfavorable outcome was especially apparent in the subgroups defined by estrogen receptor positivity, low p53 expression, and no HER-2 amplification (P < 0.0001 for all comparisons). These results indicate that elevated Cox-2 expression is more common in breast cancers with poor prognostic characteristics and is associated with an unfavorable outcome. The present findings support efforts to initiate clinical trials on the efficacy of Cox-2 inhibitors in adjuvant treatment of breast cancer.

Breast Neoplasms↗

PubMed2002

Cryopreserved chronic lymphocytic leukemia cells analyzed by multicolor fluorescence in situ hybridization after optimized mitogen stimulation.

We investigated the utility of multicolor in situ fluorescence hybridization (mFISH) on cryopreserved blood cells from 11 chronic lymphocytic leukemia (CLL) patients. The results demonstrate that an individually chosen optimized mitogen combination induces proliferation of neoplastic B-cells after cryopreservation. Abnormal cells were detected in eight samples by mFISH, and, in six samples, the abnormality could be verified by comparative genomic hybridization or interphase FISH. In addition to typical CLL abnormalities, such as del(11q) or +12, several balanced translocations and single-cell abnormalities were found. Thus, mFISH can reveal new prognostically relevant chromosome aberrations in CLL.

Cell Division↗

PubMed2002

Alterations of the SDHD gene locus in midgut carcinoids, Merkel cell carcinomas, pheochromocytomas, and abdominal paragangliomas.

Several types of endocrine tumors show frequent somatic deletions of the distal part of chromosome arm 11q, where the tumor-suppressor gene SDHD (succinate-ubiquinone oxidoreductase subunit D), constitutionally mutated in paragangliomas of the head and neck, is located. In this study, we screened 18 midgut carcinoids, 7 Merkel cell carcinomas, 46 adrenal pheochromocytomas (37 sporadic and 9 familial), and 7 abdominal paragangliomas for loss of heterozygosity (LOH) and/or mutations at the SDHD gene locus. LOH was detected in 5 out of 8 (62%) informative midgut carcinoids, in 9 out of 30 (30%) sporadic pheochromocytomas, in none of the familial pheochromocytomas (0%), and in 1 out of 6 (17%) abdominal paragangliomas. No sequence variants were detected in the pheochromocytomas or paragangliomas. However, two constitutional putative missense mutations, H50R and G12S, were detected in two midgut carcinoids, which were both associated with LOH of the other allele. The same sequence variants were also detected in two Merkel cell carcinomas. In addition, the S68S polymorphism was found to coexist with the G12S sequence variant in both cases. In conclusion, we show that alterations of the SDHD gene seem to be involved in the tumorigenesis of both midgut carcinoids and Merkel cell carcinomas.

Abdominal Neoplasms↗

PubMed2002

Evaluation of HER-2/NEU protein expression in breast cancer by immunohistochemistry: an interlaboratory study assessing the reproducibility of HER-2/NEU testing.

This study investigated the degree of interlaboratory agreement when HER-2/neu was evaluated by immunohistochemistry (IHC) on archival primary breast cancer samples. IHC for HER-2/neu was performed on the same archival tissue sections from 394 invasive primary breast cancers in two different laboratories. Both laboratories used the primary antibody NCL-CB11; however, different methods of immunostaining (antigen retrieval procedure and manual processing or no antigen retrieval and autostainer processing) as well as different scoring systems were used. Fluorescence in situ hybridization (FISH), considered as the correlation method for HER-2/neu status determination, was performed using the PathVysion kit and compared to the IHC results. Forty-eight of 394 analyzed tumors (12.2%) were scored as HER-2/neu positive in one laboratory, and 109 (27.7%) in the other laboratory where antigen retrieval was performed. Complete concordance in categorization of HER-2/neu status between the two laboratories was achieved in 333 of 394 cases (84.5%). FISH performed in 248 formalin-fixed samples revealed HER-2/neu gene amplification in 55/248 (22.2%). Concordance of FISH and IHC was found in 211/248 cases (85.1%) and 220/248 cases (88.7%) when the CB11 antibody was used without and with antigen retrieval, respectively. Both IHC methods generated similar rates of false results, but with different positive predictive values. Our data demonstrate that HER-2/neu evaluation by IHC is not a reproducible technique if there is no standardization of the procedure.

Breast Neoplasms↗

PubMed2002

Cytogenetic alterations and cytokeratin expression patterns in breast cancer: integrating a new model of breast differentiation into cytogenetic pathways of breast carcinogenesis.

The introduction of a concept proposing multiple cellular subgroups in the normal female breast, including cytokeratin 5/6 (Ck 5/6)-positive progenitor cells, offers a new explanation for the existence of highly aggressive breast cancers with and without Ck 5/6 expression. Using the tissue microarray technique, 166 breast cancer cases, all characterized by comparative genomic hybridization, were evaluated by immunohistochemistry, using 15 different antibodies (estrogen receptor, progesterone receptor, p53, Ki-67, c-erbB2, epidermal growth factor receptor, cyclins A, D1, and E, bcl-2, p21, p27, Ck 5/6, Ck 8/18, and smooth muscle actin) and chromogenic in situ hybridization for c-erbB2. Biomathematical cluster analysis was applied to confirm the conventional interpretation of the results by an independent approach. Ck 5/6-positive breast carcinomas were in general negative for estrogen receptor and progesterone receptor, were highly proliferating (as reflected by Ki67 and cyclin A), and were associated with specific protein expression patterns, such as expression of p53 and epithelial growth factor receptor (all related to more aggressive tumor behavior), which could further be demonstrated by biomathematical cluster analysis. In contrast Ck 5/6-negative breast carcinomas revealed a lower tumor proliferation rate, an increased expression of p21, p27, c-erbB2, and bcl-2, and a significantly lower number of genetic alterations, with losses of chromosomal material of 16q as the most common genetic alteration. Our data give the first hints to the hypothesis that different cellular subgroups in the female breast give rise to subgroups of breast carcinomas with differing protein expression and cytogenetic alteration patterns that may be related to clinical behavior.

Breast Neoplasms↗

PubMed2002

Chromosomal translocations involving 11q13 contribute to cyclin D1 overexpression in squamous cell carcinoma of the head and neck.

CCND1 amplification results in cyclin D1 overexpression. However, other unidentified genetic mechanisms contribute to enhanced gene expression. In the present study, 32 squamous cell carcinoma of the head and neck (SCCHN) were investigated regarding chromosomal abnormalities involving 11q13 by cytogenetic analysis, genomic CCND1 amplification by differential PCR and FISH, and cyclin D1 expression on the mRNA and protein level by differential RT-PCR and immunohistochemistry, respectively. CCND1 amplification, observed in 11 of 32 (34%) tumours, resulted in overexpression of cyclin D1 on the mRNA and/or protein level, in 3 cases in association with chromosomal translocations. In cytogenetic analysis, 4 tumours had hsr(11)(q13), all of which showed CCND1 amplification and cyclin D1 overexpression. Overexpression of cyclin D1 was detected at the mRNA level in 23 tumours (72%) and on the protein level in 25 tumours (78%). In one case a translocation was seen together with cyclin D1 overexpression on the mRNA level, without any cytogenetic or molecular signs of amplification. Furthermore, cases with cyclin D1 overexpression were frequently observed in the absence of any genomic rearrangement. We conclude that, besides amplifications, chromosomal translocations and other transcriptional or translational regulatory mechanisms are involved in CCND1 deregulation.

Biopsy↗

PubMed2002

HER-2 amplification and topoisomerase IIalpha gene aberrations as predictive markers in node-positive breast cancer patients randomly treated either with an anthracycline-based therapy or with cyclophosphamide, methotrexate, and 5-fluorouracil.

PURPOSE: The purpose of this study is to evaluate HER-2 and topoisomerase IIalpha (topo IIalpha) as candidates for predicting the activity of anthracyclines in the adjuvant treatment of breast cancer patients. EXPERIMENTAL DESIGN: In this study, we evaluated HER-2 and topo IIalpha gene aberrations by fluorescence in situ hybridization in a series of 430 primary breast cancer samples. Samples came from node-positive breast cancer patients randomly treated either with one of two anthracycline-based regimens [full-dose epirubicin-cyclophosphamide (HEC) and moderate-dose epirubicin-cyclophosphamide (EC)] or with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) in the context of a Phase III adjuvant therapy trial. Event-free survival comparisons were performed between the three study arms in the subgroups of HER-2-amplified and nonamplified tumors. An explorative analysis was also performed to evaluate the predictive value of topo IIalpha in the cohort of HER-2-amplified patients. RESULTS: HER-2 amplification was observed in 73 of the 354 evaluable samples (21%), whereas topo IIalpha amplification was found in 23 of the 61 evaluable HER-2-amplified tumors (38%). The three event-free survival comparisons were CMF versus HEC, CMF versus EC, and EC versus HEC. Hazard ratios (HRs) and 95% confidence intervals (CIs) were as follows: (a) CMF versus HEC, HR = 1.42 for HER-2-amplified tumors (95% CI, 0.54-3.76; P = 0.48) and 0.84 for HER-2-nonamplified tumors (95% CI, 0.49-1.44; P = 0.53); (b) CMF versus EC, HR = 1.65 for HER-2-amplified tumors (95% CI, 0.66-4.13; P = 0.29) and 0.66 for HER-2-nonamplified tumors (95% CI, 0.39-1.10; P = 0.11); and (c) EC versus HEC, HR = 0.93 for HER-2-amplified tumors (95% CI, 0.31-2.77, P = 0.90) and 1.33 for HER-2-nonamplified tumors (95% CI, 0.82-2.14; P = 0.25). Observed HRs suggest that the anthracycline-based therapy could be more effective than CMF in the subgroup of HER-2-amplified patients, whereas treatments could be equally active in the HER-2-nonamplified cohort. topo IIalpha evaluation suggests that the superiority of anthracyclines over CMF in HER-2-amplified patients could be confined to the subgroup of topo IIalpha-amplified tumors. CONCLUSIONS: HER-2 could have a predictive value for the activity of anthracycline-based regimens in the adjuvant therapy of breast cancer patients. The predictive value of HER-2 would most likely be related to the concomitant amplification of the topo IIalpha gene.

Aged↗