Ikumi Kitazono

Endometrial Liquid‐Based Cytology Specimens Preserve High Genome Quality for Molecular Classification After Long‐Term Storage

ABSTRACTBackgroundMolecular classification of endometrial cancer is useful for predicting prognosis. Genomic examinations are performed using formalin‐fixed paraffin‐embedded (FFPE) tissues; however, we previously reported that liquid‐based cytology (LBC) specimens can be used for next‐generation sequencing (NGS). In this study, we evaluated long‐term storage effects of LBC specimens on NGS‐based genomic profiling, including gene mutations, tumor mutation burden (TMB), and microsatellite instability (MSI).MethodsFour LBC fixatives (CellPrep, ThinPrep, CytoRich Red, and SurePath) were used to prepare NGS samples from cultured endometrioid carcinoma HEK‐251 cells. Twelve endometrial LBC specimens from patients with endometrioid carcinoma were fixed with CytoRich Red. The TMB, MSI, and gene mutations were analyzed after 1 week, 6 months, and 12 months of storage in cultured HEK‐251 cells. Paired LBC and FFPE specimens of endometrioid carcinoma stored for 15–45 months were subjected to NGS‐based analysis, and their molecular profiles were compared to those at the initial diagnosis.ResultsThe TMB and MSI did not differ during the storage periods for any of the LBC fixatives in the cultured cells; in addition to gene mutations, they were comparable between the initial and second analyses of the clinical FFPE and LBC specimens. There were no changes in the integrative diagnosis of the endometrioid carcinoma subtype classification.ConclusionLBC specimens, which preserved high‐quality genomes for molecular classification after long‐term storage, may be an alternative source of genomic examination for the integrative diagnosis of endometrial cancer.

Pelvic Carcinosarcoma Showing a Diverse Histology and Hierarchical Gene Mutation with a Common POLE Mutation to Endometrial Endometroid Carcinoma: A Case Report

POLE mutation-type endometrial cancer is characterized by an extremely high tumor mutation burden. Most POLE mutation-type endometrial cancers are histologically endometrioid carcinomas, and POLE mutation-type carcinosarcomas are rare among endometrial cancers. We report a case of endometrial and pelvic cancer in a 53-year-old woman who was analyzed using next-generating sequencing. The endometrial lesion harbored a p.T457del POLE mutation with an elevated tumor mutation burden and low microsatellite instability. The pelvic lesion showed divergent histological features, consisting of high-grade endometrioid carcinoma, neuroendocrine carcinoma, and chondrosarcoma. In addition to the common POLE mutation detected in the endometrial lesion, the pelvic lesion in each element showed additional gene mutations in a hierarchical manner. Therefore, it is indicated that the p.T457del POLE mutation is a pathogenic mutation and may be related to POLE mutation-induced carcinogenesis and divergent morphogenesis in endometrial cancer.

One-step nucleic acid amplification (OSNA) assay for detecting lymph node metastasis in cervical and endometrial cancer: a preliminary study

To evaluate the accuracy of the one-step nucleic acid amplification (OSNA) assay for the diagnosis of lymph node (LN) metastasis in uterine cancer. A total of 116 LNs from 30 patients with cervical and endometrial cancer, enrolled in this prospective study, were used. Excised LNs were cut into 4 to 6 blocks at 2 mm intervals, and nonadjacent blocks were alternately subjected to either histological examination or the OSNA assay. The concordance rate between histological examination and the OSNA assay in cervical cancer and in endometrial cancer was 95.9% and 95.2%, respectively. The sensitivity, specificity, and negative predictive value of the OSNA assay were 80%, 97.7%, and 97.7% in cervical cancer, and 85.7%, 93.3%, and 98.2% in endometrial cancer, respectively. In cervical cancer, discordant results were observed in 2 out of 49 LNs (4.1%); 1 was OSNA assay-positive and histological examination-negative, and 1 was OSNA assay-negative and histological examination-positive. In endometrial cancer, discordant results were observed in 5 out of 67 LNs (7.5%); 4 were OSNA assay-positive and histological examination-negative, and 1 was OSNA assay-negative and histological examination-positive. The OSNA assay showed high concordance rate with histological examination, sensitivity, and specificity in uterine cancer, suggesting that it could enhance the accuracy of conventional pathological examination for the detection of LN metastasis by reducing false negative rate.

Two Components of Variant Profiles in Primary Vaginal Carcinosarcoma via Next-Generation Sequencing and a Literature Review

Primary vaginal carcinosarcoma (VCS) is an extremely rare and aggressive tumor consisting of admixed malignant epithelial and mesenchymal elements. We report a case of VCS that was subjected to analysis by immunohistochemistry and next-generation sequencing (NGS). A 53-year-old woman with post-menopausal vaginal bleeding underwent surgical excision followed by concurrent chemoradiation. A well demarcated tumor was growing in a discontinuous fashion at a location some distance from both the cervix and vulva. Microscopically, the tumor consisted of adenocarcinoma components and sarcoma components consisting of a sheet-like growth of spindle-shaped cells, and we diagnosed this tumor as primary vaginal carcinosarcoma. NGS analysis of each component identified the following variants, TP53, PIK3CA, KRAS and FBXW7. A comparison of microsatellite instability (MSI) and tumor mutation burden (TMB) showed that within both tissues the sarcomatous components had a higher MSI and TMB than the carcinomatous components. This case supports “a monoclonal theory” with the genome profile being similar to other malignant mixed Müllerian tumors.

Human Papilloma Virus 18-Positive Submucosal Small Cell Neuroendocrine Carcinoma of the Vagina: An Immunohistochemical and Genomic Study

Primary vaginal neuroendocrine carcinoma (NEC) is extremely rare among female genital tract tumors. Here, we report 2 cases of vaginal small cell NEC (SCNEC) using immunohistochemistry and next-generation sequencing (NGS) analysis. The 2 patients were in their mid-to-late 70s, presented with abnormal vaginal bleeding and had a vaginal submucosal mass. The biopsied or resected tumors showed a typical neuroendocrine morphology consisting of solid nests of atypical tumor cells, with no specific organoid patterns, and proliferating in the vaginal submucosa. Immunohistochemical analysis showed strong and diffuse expression of chromogranin A, synaptophysin, and p16, but no thyroid transcription factor 1 expression. Additionally, both cases were positive for human papillomavirus (HPV) 18. An NGS-based cancer panel analysis revealed that the tumors carried NF1 and AR mutations, but no major driver mutations were detected. The results of this study suggested that HPV18 infection is linked to vaginal SCNEC.