P. J. van Diest

Reproducibility of mitosis counting in 2,469 breast cancer specimens: Results from the Multicenter Morphometric Mammary Carcinoma Project☆

The Multicenter Morphometric Mammary Carcinoma Project is a prospective study on the reproducibility and prognostic value of routine quantitative assessments, especially the mitotic activity index (MAI), the multivariate prognostic index (MPI; a combination of MAI, tumor size, and lymph node status), the mean nuclear area, and DNA ploidy assessments in patients with invasive breast cancer. Fourteen pathology laboratories providing routine services to 35 hospitals throughout The Netherlands are participating in this project. In this article, the reproducibility of MAI and MPI assessments is described. Assessment of the MAI was, according to a strict protocol, first performed in the participating laboratories; thereafter, slides were transferred to the coordination center in Amsterdam for quality control. Analysis of the reproducibility of the assessments in 2,469 patients showed correlation coefficients between 0.81 and 0.96 (mean, 0.91) for the MAI and between 0.91 and 0.97 (mean, 0.96) for the MPI. The reproducibility was fairly constant in time, although it showed a slight drop in the middle of the 2-year intake period. A prognostically relevant discrepancy in MPI (caused by differences in MAI) between the original and quality control assessments was found in only 7.2% of the cases. When analyzing the reasons for these discrepancies, a plausible explanation could be found in all cases: bad tissue processing and ignorance of or negligence in following the protocol guidelines for selection of the counting area or in the process of counting were the most important flaws. Since these errors are largely controllable, an even lower discrepancy rate is theoretically achievable. In conclusion, in a routine setting it can be learned, within a reasonable time, to perform mitosis counting in a highly reproducible way if a strict protocol is carefully followed. This opens the way for a wider application of the MAI and MPI in breast cancer patients. Motivation is, however, an important factor to obtain reproducible results, and ongoing quality control is essential to guarantee the reproducibility of the assessments.

Prognostic value of proliferation in invasive breast cancer: a review.

Breast cancer is the leading cause of death among solid tumours in women, and its incidence is increasing in the West. Adjuvant chemotherapy and hormonal treatment improve survival but have potentially serious side effects, and are costly. Because adjuvant treatment should be given to high risk patients only, and traditional prognostic factors (lymph node status, tumour size) are insufficiently accurate, better predictors of high risk and treatment response are needed. Invasive breast cancer metastasises haematogenously very early on, so many breast cancer prognosticators are directly or indirectly related to proliferation. Although studies evaluating the role of individual proliferation regulating genes have greatly increased our knowledge of this complex process, the functional end result—cells dividing—has remained the most important prognostic factor. This article reviews the prognostic value of different proliferation assays in invasive breast cancer, and concludes that increased proliferation correlates strongly with poor prognosis, irrespective of the methodology used. Mitosis counting provides the most reproducible and independent prognostic value, and Ki67/MIB1 labelling and cyclin A index are promising alternatives that need methodological fine tuning.

Reliability of intraoperative frozen section and imprint cytological investigation of sentinel lymph nodes in breast cancer

The sentinel lymph node procedure enables selective targeting of the first draining lymph node, where the initial metastases will form. A negative sentinel node (SN) predicts the absence of tumour metastases in the other regional lymph nodes with high accuracy. This means that in the case of a negative SN, regional lymph node dissection is no longer necessary. Besides saving costs, this will prevent many side‐effects of lymph node dissection. The aim of this study was to evaluate the reliability of intraoperative cytological and frozen section investigation of the SN to detect metastases. This would allow the axillary lymph node dissection to be performed in the same session as the SN procedure and the excision of the primary tumour in case of a positive SN.

Survival in Early Breast Cancer Patients Is Favorably Influenced by a Natural Humoral Immune Response to Polymorphic Epithelial Mucin

PURPOSE Polymorphic epithelial mucin (PEM or MUC1) is being studied as a vaccine substrate for the immunotherapy of patients with adenocarcinoma. The present study analyzes the incidence of naturally occurring MUC1 antibodies in early breast cancer patients and relates the presence of these antibodies in pretreatment serum to outcome of disease. MATERIALS AND METHODS We measured immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to MUC1 with an enzyme-linked immunoassay (PEM.CIg), which uses a MUC1 triple-tandem repeat peptide conjugated to bovine serum albumin, in pretreatment serum samples obtained from 154 breast cancer patients (52 with stage I disease and 102 with stage II) and 302 controls. The median disease-specific survival time of breast cancer patients was 74 months (range, 15 to 118 months). A positive test result was defined as MUC1 IgG or IgM antibody levels equal to or greater than the corresponding rounded-up median results obtained in the total breast cancer population. RESULTS A positive test result for both MUC1 IgG and IgM antibodies in pretreatment serum was associated with a significant benefit in disease-specific survival in stage I and II (P =.0116) breast cancer patients. Positive IgG and IgM MUC1 antibody levels had significant additional prognostic value to stage (P =.0437) in multivariate analysis. Disease-free survival probability did not differ significantly. However, stage II patients who tested positive for MUC1 IgG and IgM antibody and who relapsed had predominantly local recurrences or contralateral disease, as opposed to recurrences at distant sites in the patients with a negative humoral response (P =.026). CONCLUSION Early breast cancer patients with a natural humoral response to MUC1 have a higher probability of freedom from distant failure and a better disease-specific survival. MUC1 antibodies may control hematogenic tumor dissemination and outgrowth by aiding the destruction of circulating or seeded MUC1-expressing tumor cells. Vaccination of breast cancer patients with MUC1-derived (glyco)peptides in an adjuvant setting may favorably influence the outcome of disease.

Differential prognostic impact of hypoxia induced and diffuse HIF-1α expression in invasive breast cancer

Background: Intratumorous hypoxia triggers a broad cellular response mediated by the transcription factor hypoxia inducible factor 1 (HIF-1). HIF-1α concentrations increase during breast carcinogenesis, and are associated with poor prognosis. An earlier study noted two HIF-1α overexpression patterns: diffuse scattered throughout the tissue and confined to perinecrotic cells. Aims: To investigate the prognostic impact of these different HIF-1α overexpression patterns in relation to its downstream effectors carbonic anhydrase (CA) IX and glucose transporter 1 (GLUT-1). Methods: HIF-1α, CA IX, and GLUT-1 expression was studied by immunohistochemistry, including double staining for CA IX and HIF-1α. Clinical data included disease free survival, lymph node status, and tumour size. Results: HIF-1α overexpression (44% of cases) had a perinecrotic (13.5%) or diffuse staining pattern (30.5%). CA IX expression was detectable in 12.5% of breast cancers, whereas GLUT-1 expression was seen in 29%, with both showing perinecrotic membrane staining. Perinecrotic HIF-1α overexpression was highly associated with CA IX and GLUT-1 overexpression, and double staining for HIF-1α and CA IX showed strong expression in the same cells. Diffusely overexpressed HIF-1α was not associated with CA IX or GLUT-1 expression. Patients with diffuse HIF-1α staining had a significantly better prognosis than patients with perinecrotically overexpressed HIF-1α. Conclusions: Different regulation pathways of HIF-1α overexpression exist in breast cancer: (1) hypoxia induced, perinecrotic HIF-1α overexpression with strong expression of hypoxia associated genes (CA IX and GLUT-1), which is associated with a poor prognosis; and (2) diffuse HIF-1α overexpression lacking major hypoxia associated downstream effects, resulting in a more favourable prognosis.

Progression from colorectal adenoma to carcinoma is associated with non-random chromosomal gains as detected by comparative genomic hybridisation.

AIMS: Chromosomal gains and losses were surveyed by comparative genomic hybridisation (CGH) in a series of colorectal adenomas and carcinomas, in search of high risk genomic changes involved in colorectal carcinogenesis. METHODS: Nine colorectal adenomas and 14 carcinomas were analysed by CGH, and DNA ploidy was assessed with both flow and image cytometry. RESULTS: In the nine adenomas analysed, an average of 6.6 (range 1 to 11) chromosomal aberrations were identified. In the 14 carcinomas an average of 11.9 (range 5 to 17) events were found per tumour. In the adenomas the number of gains and losses was in balance (3.6 v 3.0) while in carcinomas gains occurred more often than losses (8.2 v 3.7). Frequent gains involved 13q, 7p, 8q, and 20q, whereas losses most often occurred at 18q, 4q, and 8p. Gains of 13q, 8q, and 20q, and loss of 18q occurred more often in carcinomas than in adenomas (p = 0.005, p = 0.05, p = 0.05, and p = 0.02, respectively). Aneuploid tumours showed more gains than losses (mean 9.3 v 4.9, p = 0.02), in contrast to diploid tumours where gains and losses were nearly balanced (mean 3.1 v 4.1, p = 0.5). CONCLUSIONS: The most striking difference between chromosomal aberrations in colorectal adenomas and carcinomas, as detected by CGH, is an increased number of chromosomal gains that show a nonrandom distribution. Gains of 13q and also of 20q and 8q seem especially to be involved in the progression of adenomas to carcinomas, possibly owing to low level overexpression of oncogenes at these loci.

Proliferation markers in tumours: interpretation and clinical value.

Proliferation is one of the most fundamental of biological processes because of its role in growth and in the maintenance of tissue homeostasis. In tumours especially, proliferation has traditionally received much attention. On the one hand, proliferation has been studied as an important cell biological mechanism in oncogenesis, often using rather laborious methods applicable only in experimental conditions, such as tritiated thymidine incorporation. On the other hand, assessment of proliferation has become popular in histopathology as a means of predicting the behaviour of tumours—that is, their likelihood of local recurrence, their metastatic potential, and the growth of metastases, and thereby the disease-free survival and survival to death. This is owing to the fact that diVerent methods have become available to assess certain properties of cellular proliferation that are readily available in daily histopathological practice. This has led to vast numbers of studies on the value of these methods for the diagnosis of diVerent kinds of tumours and clinical decision making. In this review we aim to provide an overview of methods currently available for assessment of proliferation, and to discuss critically their cell biological framework, their methodology, and some of the most important applications of these methods. First, however, a description of the cell cycle is necessary, to provide the context within which the diVerent methods of assessing proliferation will be interpreted.

Hypoxia-inducible factor-1α is associated with angiogenesis, and expression of bFGF, PDGF-BB, and EGFR in invasive breast cancer

Aims : Hypoxia‐inducible factor‐1 (HIF‐1) is the key transcription factor regulating the cellular response to hypoxia, including angiogenesis. Growth factors play an important role in tumour growth and angiogenesis and some have been shown to be induced by HIF‐1 in vitro. This study investigated if angiogenesis or growth factors or their receptors are associated with HIF‐1α in invasive breast cancer.

Oncogenic role of DDX3 in breast cancer biogenesis

Benzo[a]pyrene diol epoxide (BPDE), the active metabolite of benzo[a]pyrene present in tobacco smoke, is a major cancer-causing compound. To evaluate the effects of BPDE on human breast epithelial cells, we exposed an immortalized human breast cell line, MCF 10A, to BPDE and characterized the gene expression pattern. Of the differential genes expressed, we found consistent activation of DDX3, a member of the DEAD box RNA helicase family. Overexpression of DDX3 in MCF 10A cells induced an epithelial-mesenchymal-like transformation, exhibited increased motility and invasive properties, and formed colonies in soft-agar assays. Besides the altered phenotype, MCF 10A-DDX3 cells repressed E-cadherin expression as demonstrated by both immunoblots and by E-cadherin promoter-reporter assays. In addition, an in vivo association of DDX3 and the E-cadherin promoter was demonstrated by chromatin immunoprecipitation assays. Collectively, these results demonstrate that the activation of DDX3 by BPDE, can promote growth, proliferation and neoplastic transformation of breast epithelial cells.

Genetic relation of lobular carcinoma in situ, ductal carcinoma in situ, and associated invasive carcinoma of the breast

Aims—The mutual relation of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) of the breast, as accepted precursor lesions of invasive breast cancer, is controversial. Because they display genetic heterogeneity, it is not clear how genetically advanced these entities are and what causes the transition to an invasive carcinoma. Methods—Six cases of LCIS, four of them with associated lobular invasive carcinoma, four cases of intermediately differentiated DCIS with an associated invasive lobular carcinoma, and nine cases of intermediately and poorly differentiated DCIS with associated ductal invasive carcinoma were investigated by means of comparative genomic hybridisation (CGH) after microdissection and immunohistochemical staining of E-cadherin. Results—LCIS was characterised by a low average rate of copy number changes, no evidence of amplifications, and a high rate of gains and losses of chromosomal material at 1q and 16q, respectively. A high degree of genetic homology with well differentiated DCIS was obvious, as reported previously. The cases of intermediately differentiated DCIS with associated lobular invasive components and lobular differentiation revealed striking homologies, and a significant difference of E-cadherin expression. The comparison of preinvasive and invasive breast lesions, irrespective of differentiation within the same patient, revealed no specific alteration that might be associated with invasion. Genetic alterations seen in invasive carcinoma were not necessarily seen in the adjacent precursor lesions. Conclusions—These results provide strong evidence that invasive breast cancer is a disease with multiple cytogenetic subclones already present in preinvasive lesions. Moreover, specific CGH alterations associated with invasion were not observed. Furthermore, the close genetic association between well differentiated and a subgroup of intermediately differentiated DCIS and LCIS led to the hypothesis that LCIS and a subgroup of DCIS are different phenotypic forms of a common genotype.