Differential expression of p-ERM, a marker of cell polarity, in benign and neoplastic oviductal epithelium.

Serous tubal intraepithelial carcinoma (STIC) is a noninvasive phase of pelvic serous cancer at risk for metastasizing. Because of its biologic significance, its accurate distinction from nonmalignant mimics is important. Loss of cell orientation is an important feature of STIC. We sought to determine whether the immunohistochemical localization of cytoskeletal-organizing proteins phospho-ezrin-radaxin-moesin (p-ERM) would be useful in making this distinction. The benign oviductal entities (normal and p53 signatures), premalignant atypias (tubal intraepithelial lesions in transition), serous intraepithelial carcinomas (STICs), and carcinomas were analyzed for 5 staining patterns and compared. Linear or uniform luminal p-ERM staining was strongly associated with benign mucosa in contrast to STICs, in which it was lost and often replaced by nonlinear or nonuniform patterns highlighting individually cell groups or single cells. Premalignant atypias were similar to benign mucosa by p-ERM staining and retained the linear luminal pattern. This study shows, for the first time, that patterns of staining for an immunohistochemical correlate of cell polarity (p-ERM) differ between STICs, their benign counterparts and premalignant atypias that do not fulfill the criteria for STICs. If confirmed, these findings warrant further analysis of indices of cell polarity as objective markers for the diagnosis and mapping of the evolution of pelvic serous precursors. Int J Gynecol Pathol 2013 Jul; 32(4):345-52

Through the glass darkly: intraepithelial neoplasia, top-down differentiation and the road to ovarian cancer.

It is currently hoped that deaths from extra-uterine high-grade serous cancer (HGSC) will be reduced via opportunistic salpingectomy in healthy women. Accumulated data implicate the fimbria as a site of origin and descriptive molecular pathology and experimental evidence strongly support a serous carcinogenic sequence in the fallopian tube. Both direct and indirect ( surrogate ) precursors suggest the benign tube undergoes important biologic changes after menopause, acquiring abnormalities in gene expression that are often shared with malignancy, including PAX2, ALDH1, LEF1, RCN1, RUNX2, beta catenin, EZH2 and others. However, the tube can be linked to only some HGSCs, recharging arguments that nearby peritoneum/ovarian surface epithelium (POSE) also hosts progenitors to this malignancy. A major sticking point is the difference in immunophenotype between POSE and Müllerian epithelium, essentially requiring mesothelial to Müllerian differentiation prior to or during malignant transformation to HGSC. However, emerging evidence implicates an embryonic or progenitor phenotype in the adult female genital tract with the capacity to differentiate, normally or during neoplastic transformation. Recently, a putative cell of origin to cervical cancer has been identified in the squamo-columnar (SC) junction, projecting a model whereby Krt7+ embryonic progenitors give rise to immuno-phenotypically distinct progeny under stromal influences via top down differentiation. Similarly, biphasic cell differentiation can be seen in the endometrium with a parallel in the juxtaposition of mesothelial and mullerian differentiation in the ovary. An abrupt mesothelial-Mullerian transition remains to be proven, but would explain the rapid evolution, short asymptomatic interval, and absence of a defined epithelial starting point in many HGSCs. Resolving this question will require accurately distinguishing progenitor from progeny tumor cells in HGSC and pinpointing where initial transformation and trans-differentiation occurs if the POSE is an origin. Both will be critical to expectations from prophylactic salpingectomy and future approaches to pelvic serous cancer prevention. J Pathol 2013 Dec; 231(4):402-412

The PAX2-null immunophenotype defines multiple lineages with common expression signatures in benign and neoplastic oviductal epithelium.

The oviducts contain high-grade serous cancer (HGSC) precursors (serous tubal intraepithelial neoplasia or STINs), which are gamma-H2AXp - and TP53 mutation-positive. Although they express wild-type p53, secretory cell outgrowths (SCOUTs) are associated with older age and serous cancer; moreover, both STINs and SCOUTs share a loss of PAX2 expression (PAX2n ). We evaluated PAX2 expression in proliferating adult and embryonic oviductal cells, normal mucosa, SCOUTs, Walthard cell nests (WCNs), STINs, and HGSCs, and the expression of genes chosen empirically or from SCOUT expression arrays. Clones generated in vitro from embryonic gynaecological tract and adult Fallopian tube were Krt7p /PAX2n /EZH2p and underwent ciliated (PAX2n /EZH2n /FOXJ1p ) and basal (Krt7n /EZH2n /Krt5p ) differentiation. Similarly, non-ciliated cells in normal mucosa were PAX2p but became PAX2n in multi-layered epithelium undergoing ciliated or basal (WCN) cell differentiation. PAX2n SCOUTs fell into two groups: type 1 were secretory or secretory/ciliated with a 'tubal' phenotype and were ALDH1n and beta-cateninmem (membraneous only). Type 2 displayed a columnar to pseudostratified (endometrioid) phenotype, with an EZH2p , ALDH1p , beta-cateninnc (nuclear and cytoplasmic), stathminp , LEF1p , RCN1p , and RUNX2p expression signature. STINs and HGSCs shared the type 1 immunophenotype of PAX2n , ALDH1n , beta-cateninmem , but highly expressed EZH2p , LEF1p , RCN1p , and stathminp . This study, for the first time, links PAX2n with proliferating fetal and adult oviductal cells undergoing basal and ciliated differentiation and shows that this expression state is maintained in SCOUTs, STINs, and HGSCs. All three entities can demonstrate a consistent perturbation of genes involved in potential tumour suppressor gene silencing (EZH2), transcriptional regulation (LEF1), regulation of differentiation (RUNX2), calcium binding (RCN1), and oncogenesis (stathmin). This shared expression signature between benign and neoplastic entities links normal progenitor cell expansion to abnormal and neoplastic outgrowth in the oviduct and exposes a common pathway that could be a target for early prevention. Copyright (c) 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd

Variability in grading of ductal carcinoma in situ among an international group of pathologists

The prognostic value of cytonuclear grade in ductal carcinoma in situ (DCIS) is debated, partly due to high interobserver variability and the use of multiple guidelines. The aim of this study was to evaluate interobserver agreement in grading DCIS between Dutch, British, and American pathologists. Haematoxylin and eosin-stained slides of 425 women with primary DCIS were independently reviewed by nine breast pathologists based in the Netherlands, the UK, and the USA. Chance-corrected kappa (kappa(ma)) for association between pathologists was calculated based on a generalised linear mixed model using the ordinal package in R. Overall kappa(ma) for grade of DCIS (low, intermediate, or high) was estimated to be 0.50 (95% confidence interval [CI] 0.44-0.56), indicating a moderate association between pathologists. When the model was adjusted for national guidelines, the association for grade did not change (kappa(ma) = 0.53; 95% CI 0.48-0.57); subgroup analysis for pathologists using the UK pathology guidelines only had significantly higher association (kappa(ma) = 0.58; 95% CI 0.56-0.61). To assess if concordance of grading relates to the expression of the oestrogen receptor (ER) and HER2, archived immunohistochemistry was analysed on a subgroup (n = 106). This showed that non-high grade according to the majority opinion was associated with ER positivity and HER2 negativity (100 and 89% of non-high grade cases, respectively). In conclusion, DCIS grade showed only moderate association using whole slide images scored by nine breast pathologists. As therapeutic decisions and inclusion in ongoing clinical trials are guided by DCIS grade, there is a pressing need to reduce interobserver variability in grading. ER and HER2 might be supportive to prevent the accidental and unwanted inclusion of high-grade DCIS in such trials