Hilde Langseth

Differential levels of circulating RNAs prior to endometrial cancer diagnosis

AbstractEndometrial cancer (EC) is one of the most common female cancers and there is currently no routine screening strategy for early detection. An altered abundance of circulating microRNAs (miRNAs) and other RNA classes have the potential as early cancer biomarkers. We analyzed circulating RNA levels using small RNA sequencing, targeting RNAs in the size range of 17–47 nucleotides, in EC patients with samples collected prior to diagnosis compared to cancer‐free controls. The analysis included 316 cases with samples collected 1–11 years prior to EC diagnosis, and 316 matched controls, both from the Janus Serum Bank cohort in Norway. We identified differentially abundant (DA) miRNAs, isomiRs, and small nuclear RNAs between EC cases and controls. The top EC DA miRNAs were miR‐155‐5p, miR‐200b‐3p, miR‐589‐5p, miR‐151a‐5p, miR‐543, miR‐485‐5p, miR‐625‐p, and miR‐671‐3p. miR‐200b‐3p was previously reported to be among one of the top miRNAs with higher abundance in EC cases. We observed 47, 41, and 32 DA miRNAs for EC interacting with BMI, smoking status, and physical activity, respectively, including two miRNAs (miR‐223‐3p and miR‐29b‐3p) interacting with all three factors. The circulating RNAs are altered and show temporal dynamics prior to EC diagnosis. Notably, DA miRNAs for EC had the lowest q‐value 4.39–6.66 years before diagnosis. Enrichment analysis of miRNAs showed that signaling pathways Fc epsilon RI, prolactin, toll‐like receptor, and VEGF had the strongest associations.

A Prospective Study Consortium for the Discovery and Validation of Early Detection Markers for Ovarian Cancer – Baseline Findings for CA125

Abstract Purpose: Epithelial ovarian cancer (EOC) is a lethal malignancy. Cancer antigen 125 (CA125), the “best” available marker for detecting EOC, has insufficient sensitivity and specificity for earlier-stage disease and is not a meaningful screening tool, motivating the search for further biomarkers. Cancer biomarker discovery is enhanced by “omics” technologies. Discovery studies for EOC biomarkers should be conducted in prediagnosis blood samples from prospective cohorts to maximize the likelihood of identifying markers that can detect disease before usual diagnosis and in earlier disease stage while reducing methodologic biases. Experimental Design: Individual cohorts with prediagnosis blood samples have insufficient sample size for such studies. Thus, we established “Prospective Early Detection Consortium for Ovarian Cancer” (“PREDICT”)—a collaboration of nine prospective studies—to assemble a sufficient number of EOC cases with blood samples collected ≤18 months before diagnosis plus controls. The 457 cases and 1,687 controls have circulating CA125 measured using a clinical assay. Results: The discrimination capacity for single CA125 measurements in samples collected <6 months prior to diagnosis was high (AUC; PREDICT overall = 0.92; range across cohorts of nonpregnant individuals = 0.89–0.98) and declined with extended time between blood collection and diagnosis. Between-cohort variability in CA125 levels and predictive performance was observed. Conclusions: Ongoing investigations in PREDICT are evaluating the early detection potential of tumor-associated autoantibodies and miRNAs using CA125 as a benchmark. PREDICT is a well-characterized resource for identifying and validating detection markers for EOC that may then be used in multimodal screening as a complement to CA125 and combined with imaging.