Combined image and genomic analysis of high-grade serous ovarian cancer reveals PTEN loss as a common driver event and prognostic classifier.

BACKGROUND: TP53 and BRCA1/2 mutations are the main drivers in high-grade serous ovarian carcinoma (HGSOC). We hypothesise that combining tissue phenotypes from image analysis of tumour sections with genomic profiles could reveal other significant driver events. RESULTS: Automatic estimates of stromal content combined with genomic analysis of TCGA HGSOC tumours show that stroma strongly biases estimates of PTEN expression. Tumour-specific PTEN expression was tested in two independent cohorts using tissue microarrays containing 521 cases of HGSOC. PTEN loss or downregulation occurred in 77% of the first cohort by immunofluorescence and 52% of the validation group by immunohistochemistry, and is associated with worse survival in a multivariate Cox-regression model adjusted for study site, age, stage and grade. Reanalysis of TCGA data shows that hemizygous loss of PTEN is common (36%) and expression of PTEN and expression of androgen receptor are positively associated. Low androgen receptor expression was associated with reduced survival in data from TCGA and immunohistochemical analysis of the first cohort. CONCLUSION: PTEN loss is a common event in HGSOC and defines a subgroup with significantly worse prognosis, suggesting the rational use of drugs to target PI3K and androgen receptor pathways for HGSOC. This work shows that integrative approaches combining tissue phenotypes from images with genomic analysis can resolve confounding effects of tissue heterogeneity and should be used to identify new drivers in other cancers.

Molecular profiling of human mammary gland links breast cancer risk to a p27(+) cell population with progenitor characteristics.

Early full-term pregnancy is one of the most effective natural protections against breast cancer. To investigate this effect, we have characterized the global gene expression and epigenetic profiles of multiple cell types from normal breast tissue of nulliparous and parous women and carriers of BRCA1 or BRCA2 mutations. We found significant differences in CD44(+) progenitor cells, where the levels of many stem cell-related genes and pathways, including the cell-cycle regulator p27, are lower in parous women without BRCA1/BRCA2 mutations. We also noted a significant reduction in the frequency of CD44(+)p27(+) cells in parous women and showed, using explant cultures, that parity-related signaling pathways play a role in regulating the number of p27(+) cells and their proliferation. Our results suggest that pathways controlling p27(+) mammary epithelial cells and the numbers of these cells relate to breast cancer risk and can be explored for cancer risk assessment and prevention.

Evolutionary pathways in BRCA1-associated breast tumors.

BRCA1-associated breast tumors display loss of BRCA1 and frequent somatic mutations of PTEN and TP53. Here we describe the analysis of BRCA1, PTEN, and p53 at the single cell level in 55 BRCA1-associated breast tumors and computational methods to predict the relative temporal order of somatic events, on the basis of the frequency of cells with single or combined alterations. Although there is no obligatory order of events, we found that loss of PTEN is the most common first event and is associated with basal-like subtype, whereas in the majority of luminal tumors, mutation of TP53 occurs first and mutant PIK3CA is rarely detected. We also observed intratumor heterogeneity for the loss of wild-type BRCA1 and increased cell proliferation and centrosome amplification in the normal breast epithelium of BRCA1 mutation carriers. Our results have important implications for the design of chemopreventive and therapeutic interventions in this high-risk patient population.

Gynecologic oncology training systems in Europe: a report from the European network of young gynaecological oncologists.

OBJECTIVE: The objectives of the study were to highlight some of the differences in training systems and opportunities for training in gynecologic oncology across Europe and to draw attention to steps that can be taken to improve training prospects and experiences of European trainees in gynecologic oncology. METHODS: The European Network of Young Gynaecological Oncologists national representatives from 34 countries were asked to review and summarize the training system in their countries of origin and fulfill a mini-questionnaire evaluating different aspects of training. We report analysis of outcomes of the mini-questionnaire and subsequent discussion at the European Network of Young Gynaecological Oncologists national representatives Asian Pacific Organization for Cancer Prevention meeting in Istanbul (April 2010). RESULTS: Training fellowships in gynecologic oncology are offered by 18 countries (53%). The median duration of training is 2.5 years (interquartile range, 2.0-3.0 years). Chemotherapy administration is part of training in 70.5% (24/34) countries. Most of the countries (26/34) do not have a dedicated national gynecologic-oncology journal. All trainees reported some or good access to training in advanced laparoscopic surgical techniques, whereas 41% indicated no access, and 59% some access to training opportunities in robotic surgery. European countries were grouped into 3 different categories on the basis of available training opportunities in gynecologic oncology: well-structured, moderately structured, and loosely structured training systems. CONCLUSIONS: There is a need for further harmonization and standardization of training programs and structures in gynecologic oncology across Europe. This is of particular relevance for loosely structured countries that lag behind the moderately structured and well-structured ones.

Increased transglutaminase 2 and GLUT-1 expression in breast tumors not susceptible to chemoprevention with antioxidants.

GOALS: Expression of GLUT-1 and transglutaminase 2 is increased in aggressive breast cancer, whereas claudin-1, which is expressed in normal tissues, is absent in such tumors. This experimental study was undertaken to establish the aggressiveness and prognosis of DMBA-induced mammary tumors in female Wistar rats based on the assessment of these markers. MATERIALS AND METHODS: The rats were divided into two groups, a control group (n = 70) and a chemoprevention group (n = 70). Breast tumors were induced in both groups by administration of 7,12-dimethylbenz[a] anthracene (DMBA). The chemoprevention group also received alpha-tocopherol and a solution of micronutrients containing ascorbic acid and selenium. Neoplastic lesions of both groups were randomly selected for immunohistochemical assessment of the expression of GLUT-1, transglutaminase 2 and claudin-1. RESULTS: A higher proportion of mammary tumors expressed GLUT-1 and transglutaminase 2 in the chemoprevention group. Claudin-1 expression was absent in all tumors of both groups. CONCLUSIONS: These results are suggestive of increased aggressiveness of tumors not susceptible to chemoprevention by the agents used in this study.