Integration of aCGH and gene expression data identified copy number aberrations and novel genes with prognostic potential in OAC.

BACKGROUND: PTEN loss is a putative driver in histotypes of ovarian cancer (high-grade serous (HGSOC), endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), low-grade serous (LGSOC)). We aimed to characterise PTEN expression as a biomarker in epithelial ovarian cancer in a large population-based study. METHODS: Tumours from 5400 patients from a multicentre observational, prospective cohort study of the Ovarian Tumour Tissue Analysis Consortium were used to evaluate associations between immunohistochemical PTEN patterns and overall survival time, age, stage, grade, residual tumour, CD8+ tumour-infiltrating lymphocytes (TIL) counts, expression of oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) by means of Cox proportional hazard models and generalised Cochran-Mantel-Haenszel tests. RESULTS: Downregulation of cytoplasmic PTEN expression was most frequent in ENOC (most frequently in younger patients; p value = 0.0001) and CCOC and was associated with longer overall survival in HGSOC (hazard ratio: 0.78, 95% CI: 0.65-0.94, p value = 0.022). PTEN expression was associated with ER, PR and AR expression (p values: 0.0008, 0.062 and 0.0002, respectively) in HGSOC and with lower CD8 counts in CCOC (p value < 0.0001). Heterogeneous expression of PTEN was more prevalent in advanced HGSOC (p value = 0.019) and associated with higher CD8 counts (p value = 0.0016). CONCLUSIONS: PTEN loss is a frequent driver in ovarian carcinoma associating distinctly with expression of hormonal receptors and CD8+ TIL counts in HGSOC and CCOC histotypes.

Despite being common in epithelial malignancies, the timing of receptor tyrosine kinase (RTK) up-regulation is poorly understood and therefore hampers the identification of the receptor to target for effective treatment. We aimed to determine if RTK expression changes were early events in carcinogenesis. Oesophageal adenocarcinoma and its pre-invasive lesion, Barrett's oesophagus, were used for immunohistochemical analysis of the RTK panel, EGFR, ErbB2, ErbB3, Met, and FGFR2, by utilizing a cohort of patients with invasive disease (n = 367) and two cohorts with pre-invasive disease, one cross-sectional (n = 110) and one longitudinal in time (n = 91). The results demonstrated that 51% of oesophageal adenocarcinomas overexpressed at least one of the RTK panel, with 21% of these overexpressing multiple receptors. Up-regulation of RTK expression was an early event corresponding with low-grade dysplasia development (25% in areas without dysplasia versus 63% in low-grade dysplasia, p < 0.001). There was a trend for an increase in the prevalence of concomitant overexpression of multiple receptors as intestinal metaplasia progressed to low-grade dysplasia, 7% versus 10%; and from low-grade dysplasia to high-grade dysplasia, 10% versus 19% (p = 0.06 and 0.24, respectively). The timing of receptor up-regulation varied; FGFR, ErbB2, and Met overexpression occurred as dysplasia first developed, whilst EGFR overexpression was predominately seen in invasive disease and ErbB3 overexpression was uniformly rare. We provide evidence for a frequent and early role for multiple different RTKs in oesophageal carcinogenesis. Given the early timing of receptor deregulation, inhibiting RTKs in pre-invasive disease may also represent a novel and effective chemopreventive strategy.