Wolter Oosterhuis

Within SPIDIA, an EC FP7 project aimed to improve pre analytic procedures, the PAXgene Tissue System (PAXgene), was designed to improve tissue quality for parallel molecular and morphological analysis. Within the SPIDIA project promising results were found in both genomic and proteomic experiments with PAXgene-fixed and paraffin embedded tissue derived biomolecules. But, for this technology to be accepted for use in both clinical and basic research, it is essential that its adequacy for preserving morphology and antigenicity is validated relative to formalin fixation. It is our aim to assess the suitability of PAXgene tissue fixation for (immuno)histological methods. Normal human tissue specimens (n = 70) were collected and divided into equal parts for fixation either with formalin or PAXgene. Sections of the obtained paraffin-embedded tissue were cut and stained. Morphological aspects of PAXgene-fixed tissue were described and also scored relative to formalin-fixed tissue. Performance of PAXgene-fixed tissue in immunohistochemical and in situ hybridization assays was also assessed relative to the corresponding formalin-fixed tissues. Morphology of PAXgene-fixed paraffin embedded tissue was well preserved and deemed adequate for diagnostics in most cases. Some antigens in PAXgene-fixed and paraffin embedded sections were detectable without the need for antigen retrieval, while others were detected using standard, formalin fixation based, immunohistochemistry protocols. Comparable results were obtained with in situ hybridization and histochemical stains. Basically all assessed histological techniques were found to be applicable to PAXgene-fixed and paraffin embedded tissue. In general results obtained with PAXgene-fixed tissue are comparable to those of formalin-fixed tissue. Compromises made in morphology can be called minor compared to the advantages in the molecular pathology possibilities.

Background: The primary aim of the study was to investigate prognosis and long-term survival in young breast cancer patients with a BRCA1 or BRCA2 germline mutation compared with noncarriers. The secondary aim was to investigate whether differences in survival originate from associations with tumor characteristics, second cancers, and/or treatment response. Methods: We established a cohort of invasive breast cancer patients diagnosed younger than age 50 years in 10 Dutch hospitals between 1970 and 2003. BRCA1/2 testing of most prevalent mutations was mainly done using DNA isolate from formalin-fixed paraffin-embedded nontumor tissue. Survival estimates were derived using Cox regression and competing risk models. Results: In 6478 breast cancer patients, we identified 3.2% BRCA1 and 1.2% BRCA2 mutation carriers. BRCA1 mutation carriers had a worse overall survival independent of clinico-pathological/treatment characteristics, compared with noncarriers (adjusted hazard ratio [HR] = 1.20, 95% confidence interval [CI] = 0.97 to 1.47), though only statistically significant in the first five years of follow-up (adjusted HR = 1.40, 95% CI = 1.07 to 1.84). A large part of the worse survival was explained by incidence of ovarian cancers. Breast cancer-specific, disease-free, and metastasis-free survival results were less pronounced and mostly statistically nonsignificant but in the same direction with those of overall survival. Overall survival was worse, although not statistically significantly, within the ER-negative or ER-positive, grade 3, and small tumor subgroups. The worse survival was most pronounced in non-chemotherapy-treated patients (adjusted HR = 1.54, 95% CI = 1.08 to 2.19). Power for BRCA2 mutation carriers was limited; only after five years' follow-up overall survival was worse (adjusted HR = 1.47, 95% CI = 1.00 to 2.17). Conclusions: BRCA1/2 mutation carriers diagnosed with breast cancer before age 50 years are prone to a worse survival, which is partly explained by differences in tumor characteristics, treatment response, and second ovarian cancers.

Intercellular contacts, mediated by E-cadherin, are essential for germ cell migration and maturation. Furthermore, it has been suggested that decrease or loss of E-cadherin correlates with tumour progression and invasive behaviour. beta-catenin is involved in a number of different processes, including cell--cell interaction when bound to cadherins, and determination of cell fate in pluripotent cells when activated via the Wnt signal-transduction pathway. To shed more light on the role of these factors in normal fetal germ cell development and the pathogenesis of germ cell tumours (GCTs), the present study investigated the presence and localization of E-cadherin and beta-catenin by immunohistochemistry. E-cadherin was only weakly expressed in or absent from fetal germ cells of the second and third trimesters, and was not expressed in carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/ITGCNU) and gonadoblastoma, the precursor of an invasive GCT in dysgenetic gonads. In GCTs, it was generally not expressed in seminoma and dysgerminoma, but was found in the vast majority of non-seminoma cells. beta-catenin was found in the cytoplasm of fetal germ cells at all gestational ages and in spermatogenesis in post-pubertal testes. It was also present in CIS/ITGCNU and gonadoblastoma. Whereas seminomas and dysgerminoma were negative, non-seminoma cells were frequently found to express beta-catenin. Expression of both factors therefore reflects the degree of differentiation of these tumours. No differences for either E-cadherin or beta-catenin were observed between samples of tumours resistant or sensitive to chemotherapy, and E-cadherin expression did not correlate with vascular invasion. E-cadherin and beta-catenin therefore play a role in both normal and malignant germ cell development and differentiation that warrants further investigation, but they seem to be of limited value as predictive or prognostic factors in GCTs.