Jorma Isola

Inherited susceptibility to uterine leiomyomas and renal cell cancer

Herein we report the clinical, histopathological, and molecular features of a cancer syndrome with predisposition to uterine leiomyomas and papillary renal cell carcinoma. The studied kindred included 11 family members with uterine leiomyomas and two with uterine leiomyosarcoma. Seven individuals had a history of cutaneous nodules, two of which were confirmed to be cutaneous leiomyomatosis. The four kidney cancer cases occurred in young (33- to 48-year-old) females and displayed a unique natural history. All these kidney cancers displayed a distinct papillary histology and presented as unilateral solitary lesions that had metastasized at the time of diagnosis. Genetic-marker analysis mapped the predisposition gene to chromosome 1q. Losses of the normal chromosome 1q were observed in tumors that had occurred in the kindred, including a uterine leiomyoma. Moreover, the observed histological features were used as a tool to diagnose a second kindred displaying the phenotype. We have shown that predisposition to uterine leiomyomas and papillary renal cell cancer can be inherited dominantly through the hereditary leiomyomatosis and renal cell cancer (HLRCC) gene. The HLRCC gene maps to chromosome 1q and is likely to be a tumor suppressor. Clinical, histopathological, and molecular tools are now available for accurate detection and diagnosis of this cancer syndrome.

Poor prognosis in carcinoma is associated with a gene expression signature of aberrant PTEN tumor suppressor pathway activity

Pathway-specific therapy is the future of cancer management. The oncogenic phosphatidylinositol 3-kinase (PI3K) pathway is frequently activated in solid tumors; however, currently, no reliable test for PI3K pathway activation exists for human tumors. Taking advantage of the observation that loss of PTEN, the negative regulator of PI3K, results in robust activation of this pathway, we developed and validated a microarray gene expression signature for immunohistochemistry (IHC)-detectable PTEN loss in breast cancer (BC). The most significant signature gene was PTEN itself, indicating that PTEN mRNA levels are the primary determinant of PTEN protein levels in BC. Some PTEN IHC-positive BCs exhibited the signature of PTEN loss, which was associated to moderately reduced PTEN mRNA levels cooperating with specific types of PIK3CA mutations and/or amplification of HER2. This demonstrates that the signature is more sensitive than PTEN IHC for identifying tumors with pathway activation. In independent data sets of breast, prostate, and bladder carcinoma, prediction of pathway activity by the signature correlated significantly to poor patient outcome. Stathmin, encoded by the signature gene STMN1, was an accurate IHC marker of the signature and had prognostic significance in BC. Stathmin was also pathway-pharmacodynamic in vitro and in vivo. Thus, the signature or its components such as stathmin may be clinically useful tests for stratification of patients for anti-PI3K pathway therapy and monitoring therapeutic efficacy. This study indicates that aberrant PI3K pathway signaling is strongly associated with metastasis and poor survival across carcinoma types, highlighting the enormous potential impact on patient survival that pathway inhibition could achieve.

Molecular cytogenetics of primary breast cancer by CGH

Comparative genomic hybridization (CGH) reveals DNA sequence copy number changes that are shared among the different cell subpopulations present in a tumor and may help to delineate the average progression pathways of breast cancer. Previous CGH studies of breast cancer have concentrated on selected subgroups of breast cancer. Here, 55 unselected primary breast carcinomas were analyzed using optimized quality‐controlled CGH procedures. Gains of 1q (67%) and 8q (49%) were the most frequent aberrations. Other recurrent gains were found at 33 chromosomal regions, with 16p, 5p12–14, 19q, 11q13–14, 17q12, 17q22–24, 19p, and 20q13 being most often (>18%) involved. Losses found in >18% of the tumors involved 8p, 16q, 13q, 17p, 9p, Xq, 6q, 11q, and 18q. The total number of aberrations per tumor was highest in poorly differentiated (P = 0.01) and in DNA aneuploid (P = 0.05) tumors. The high frequency of 1q gains and presence of +1q as the sole abnormality suggest that it is an early genetic event. In contrast, gains of 8q were most common in genetically and phenotypically advanced breast cancers. The vast majority of breast cancers (80%) have gains of 1q, 8q, or both, and 3 changes (+1q, +8q, or −13q) account for 91% of the tumors. In conclusion, CGH results indicate that certain chromosomal imbalances are very often selected for, sometimes in a preferential order, during the progression of breast cancer. Further studies of such common changes may form the basis for a molecular cytogenetic classification of breast cancer. Genes Chromosomes Cancer 21:177–184, 1998.

Chromogenic in situ hybridization: a practical alternative for fluorescence in situ hybridization to detect HER-2/neu oncogene amplification in archival breast cancer samples.

Determination of HER-2/neu oncogene amplification has become necessary for selection of breast cancer patients for trastuzumab (Herceptin) therapy. Fluorescence in situ hybridization (FISH) is currently regarded as a gold standard method for detecting HER-2/neu amplification, but it is not very practical for routine histopathological laboratories. We evaluated a new modification of in situ hybridization, the chromogenic in situ hybridization (CISH), which enables detection of HER-2/neu gene copies with conventional peroxidase reaction. Archival formalin-fixed paraffin-embedded tumor tissue sections were pretreated (by heating in a microwave oven and using enzyme digestion) and hybridized with a digoxigenin-labeled DNA probe. The probe was detected with anti-digoxigenin fluorescein, anti-fluorescein peroxidase, and diaminobenzidine. Gene copies visualized by CISH could be easily distinguished with a x40 objective in hematoxylin-stained tissue sections. HER-2/neu amplification typically appeared as large peroxidase-positive intranuclear gene copy clusters. CISH and FISH (according to Vysis, made from frozen pulverized tumor samples) correlated well in a series of 157 breast cancers (kappa coefficient, 0.81). The few different classifications were mostly because of low-level amplifications by FISH that were negative by CISH and immunohistochemistry with monoclonal antibody CB-11. We conclude that CISH, using conventional bright-field microscopy in evaluation, is a useful alternative for determination of HER-2/neu amplification in paraffin-embedded tumor samples, especially for confirming the immunohistochemical staining results.

Fluorouracil, Epirubicin, and Cyclophosphamide With Either Docetaxel or Vinorelbine, With or Without Trastuzumab, As Adjuvant Treatments of Breast Cancer: Final Results of the FinHer Trial

PURPOSE Docetaxel has not been compared with vinorelbine as adjuvant treatment of early breast cancer. Efficacy and long-term safety of a short course of adjuvant trastuzumab administered concomitantly with chemotherapy for human epidermal growth factor receptor 2 (HER2) -positive cancer are unknown. PATIENTS AND METHODS One thousand ten women with axillary node-positive or high-risk node-negative breast cancer were randomly assigned to receive three cycles of docetaxel or vinorelbine, followed in both groups by three cycles of fluorouracil, epirubicin, and cyclophosphamide (FEC). Women with HER2-positive cancer (n = 232) were further assigned to either receive or not receive trastuzumab for 9 weeks with docetaxel or vinorelbine. The median follow-up time was 62 months after random assignment. RESULTS Women assigned to docetaxel had better distant disease-free survival (DDFS) than those assigned to vinorelbine (hazard ratio [HR] = 0.66; 95% CI, 0.49 to 0.91; P = .010). In the subgroup of HER2-positive disease, patients treated with trastuzumab tended to have better DDFS than those treated with chemotherapy only (HR = 0.65; 95% CI, 0.38 to 1.12; P = .12; with adjustment for presence of axillary nodal metastases, HR = 0.57; P = .047). In exploratory analyses, docetaxel, trastuzumab, and FEC improved DDFS compared with docetaxel plus FEC (HR = 0.32; P = .029) and vinorelbine, trastuzumab, and FEC (HR = 0.31; P = .020). The median left ventricular ejection fraction of trastuzumab-treated patients remained unaltered during the 5-year follow-up; only one woman treated with trastuzumab was diagnosed with a heart failure. CONCLUSION Adjuvant treatment with docetaxel improves DDFS compared with vinorelbine. A brief course of trastuzumab administered concomitantly with docetaxel is safe and effective and warrants further evaluation.

Prognostic significance of HER-2 oncoprotein expression in breast cancer: a 30-year follow-up.

PURPOSE To study retrospectively the long-term prognostic significance of HER-2 oncoprotein expression in breast cancer (BC). PATIENTS AND METHODS Two hundred nine consecutive female patients with invasive operable BC from a defined urban population were observed for a median of 30 years. Tissue expression of HER-2 oncoprotein was demonstrated by using an immunoperoxidase procedure. RESULTS Fifty-five (26%) patients had cancer and a positive HER-2 oncoprotein stain reaction. They had significantly worse 10- and 25-year survival rates than those patients who had a negative stain reaction in their cancer (31% v 48% and 31% v 39%, respectively; P = .004). HER-2 expression was also associated with a poorer survival among patients who had axillary nodal metastases (P = .003; n = 104), but not among those patients who did not have metastases. HER-2 expression was related to the ductal histologic type, poor histologic grade, and high mitotic count, but not to tumor size, axillary nodal status, DNA ploidy, or S-phase fraction (SPF). In a multivariate analysis among patients with nodal metastases, HER-2 expression was an independent prognostic factor (P = .04) that predicted poor survival. However, if the entire series was entered onto the analysis, it did not emerge as an independent factor. CONCLUSIONS HER-2 oncoprotein expression has long-term prognostic significance for predicting poor survival in BC, and it has an independent prognostic value among patients who presented with axillary nodal metastases. This result is contradictory to the argument that HER-2 expression is only a marker for drug resistance because the patients were not given adjuvant drug therapy.

Estrogen Receptor β Is Coexpressed with ERα and PR and Associated with Nodal Status, Grade, and Proliferation Rate in Breast Cancer

The role of estrogen (ER) and progesterone receptors (PR) in breast cancer is well established. Identification of the second human estrogen receptor, the estrogen receptor β (ERβ), prompted us to evaluate its role in breast cancer. We studied the expression of ERβ by immunohistochemistry and mRNA in situ hybridization in 92 primary breast cancers and studied its association with ERα, PR, and various other clinicopathological factors. Sixty percent of tumors were defined as ERβ-positive (nuclear staining in >20% of the cancer cells). Normal ductal epithelium and 5 of 7 intraductal cancers were also found to express ERβ. Three-fourths of the ERα- and PR-positive tumors were positive for ERβ, whereas ERα and PR were positive in 87% and 67. of ERβ-positive tumors, respectively. ERβ was associated with negative axillary node status ( P P = 0.0003), low S-phase fraction ( P = 0.0003), and premenopausal status ( P = 0.04). In conclusion, the coexpression of ERβ with ERα and PR as well as its association with the other indicators of low biological aggressiveness of breast cancer suggest that ERβ-positive tumors are likely to respond to hormonal therapy. The independent predictive value of ERβ remains to be established.

Recurrent gross mutations of the PTEN tumor suppressor gene in breast cancers with deficient DSB repair

Basal-like breast cancer (BBC) is a subtype of breast cancer with poor prognosis. Inherited mutations of BRCA1, a cancer susceptibility gene involved in double-strand DNA break (DSB) repair, lead to breast cancers that are nearly always of the BBC subtype; however, the precise molecular lesions and oncogenic consequences of BRCA1 dysfunction are poorly understood. Here we show that heterozygous inactivation of the tumor suppressor gene Pten leads to the formation of basal-like mammary tumors in mice, and that loss of PTEN expression is significantly associated with the BBC subtype in human sporadic and BRCA1-associated hereditary breast cancers. In addition, we identify frequent gross PTEN mutations, involving intragenic chromosome breaks, inversions, deletions and micro copy number aberrations, specifically in BRCA1-deficient tumors. These data provide an example of a specific and recurrent oncogenic consequence of BRCA1-dependent dysfunction in DNA repair and provide insight into the pathogenesis of BBC with therapeutic implications. These findings also argue that obtaining an accurate census of genes mutated in cancer will require a systematic examination for gross gene rearrangements, particularly in tumors with deficient DSB repair.

ImmunoRatio: a publicly available web application for quantitative image analysis of estrogen receptor (ER), progesterone receptor (PR), and Ki-67

IntroductionAccurate assessment of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 is essential in the histopathologic diagnostics of breast cancer. Commercially available image analysis systems are usually bundled with dedicated analysis hardware and, to our knowledge, no easily installable, free software for immunostained slide scoring has been described. In this study, we describe a free, Internet-based web application for quantitative image analysis of ER, PR, and Ki-67 immunohistochemistry in breast cancer tissue sections.MethodsThe application, named ImmunoRatio, calculates the percentage of positively stained nuclear area (labeling index) by using a color deconvolution algorithm for separating the staining components (diaminobenzidine and hematoxylin) and adaptive thresholding for nuclear area segmentation. ImmunoRatio was calibrated using cell counts defined visually as the gold standard (training set, n = 50). Validation was done using a separate set of 50 ER, PR, and Ki-67 stained slides (test set, n = 50). In addition, Ki-67 labeling indexes determined by ImmunoRatio were studied for their prognostic value in a retrospective cohort of 123 breast cancer patients.ResultsThe labeling indexes by calibrated ImmunoRatio analyses correlated well with those defined visually in the test set (correlation coefficient r = 0.98). Using the median Ki-67 labeling index (20%) as a cutoff, a hazard ratio of 2.2 was obtained in the survival analysis (n = 123, P = 0.01). ImmunoRatio was shown to adapt to various staining protocols, microscope setups, digital camera models, and image acquisition settings. The application can be used directly with web browsers running on modern operating systems (e.g., Microsoft Windows, Linux distributions, and Mac OS). No software downloads or installations are required. ImmunoRatio is open source software, and the web application is publicly accessible on our website.ConclusionsWe anticipate that free web applications, such as ImmunoRatio, will make the quantitative image analysis of ER, PR, and Ki-67 easy and straightforward in the diagnostic assessment of breast cancer specimens.

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

Knowledge of HER2 status is a prerequisite when considering a patients 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.