title: Target-enriched next-generation sequencing reveals differences between primary and secondary ovarian tumors in formalin-fixed, paraffin-embedded tissue.
abstract: Differentiating primary endometrioid or mucinous ovarian tumors from secondary ovarian tumors can be challenging. We compared somatic mutation profiles of primary and secondary ovarian cancers to investigate if these profiles can help diagnose ovarian tumors. Cancer-related genes (n = 115) were screened by target-enriched next-generation sequencing in formalin-fixed, paraffin-embedded tumor tissue from 43 primary endometrioid and mucinous ovarian carcinomas and 28 proven colorectal cancer metastases to the ovary. Results were validated by high-resolution melting curve analysis and Sanger sequencing. TP53, NOTCH1, PIK3CA, and FAT4 versus APC, TP53, KRAS, and FAT4 mutations were the most common in the primary ovarian tumors and ovarian colorectal cancer metastases, respectively. An inactivating APC mutation was found in 4.7% of primary ovarian tumors (2 of 43; 95% CI, 1.6%-10.9%). In contrast, inactivating APC mutations were identified in 71% of colorectal cancer metastases (20 of 28; 95% CI, 55%-88%) (P < 0.001; sensitivity: 71.4%, 95% CI, 51.1%-86.0%; specificity: 95.4%, 95% CI, 82.9%-99.1%). Loss of heterozygosity and APC promoter hypermethylation did not differ significantly between the primary and secondary ovarian tumors. NOTCH1 mutations were observed specifically in primary ovarian tumors, although at a low frequency, but not in metastases (6 of 41; 14.6%; 95% CI, 3.8%-25.4%). APC mutation analysis can be used to differentiate primary endometrioid and mucinous ovarian tumors from colorectal cancer metastases to the ovary.
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Stijn
authors.initials: S
authors.lastname: Crobach
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Dina
authors.initials: D
authors.lastname: Ruano
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ronald
authors.initials: R
authors.lastname: van Eijk
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Fleuren
authors.affiliation: Laboratory for Diagnostic Genome Analysis (LDGA), Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Minderhout
authors.affiliation: Laboratory for Diagnostic Genome Analysis (LDGA), Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ronelle
authors.initials: R
authors.lastname: Snowdowne
authors.affiliation: Laboratory for Diagnostic Genome Analysis (LDGA), Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Carli
authors.initials: C
authors.lastname: Tops
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Tom
authors.initials: T
authors.lastname: van Wezel
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands. Electronic address: j.morreau@lumc.nl.
authors.forename: Hans
authors.initials: H
authors.lastname: Morreau
mesh_terms: D004252:DNA Mutational Analysis; D005260:Female; D005557:Formaldehyde; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000556:secondary; D016612:Paraffin Embedding; D016707:Tissue Fixation
chemical_list: D005557:Formaldehyde