Junki Koike

Immunosensitivity and specificity of insulinoma-associated protein 1 (INSM1) for neuroendocrine neoplasms of the uterine cervix

Previously, we reported that insulinoma-associated protein 1 (INSM1) immunohistochemistry (IHC) showed high sensitivity for neuroendocrine carcinoma of the uterine cervix and was an effective method for histopathological diagnosis, but that its specificity remained to be verified. Therefore, the aim was to verify the specificity of INSM1 IHC for a large number of non-neuroendocrine neoplasia (NEN) of the cervix. RNA sequences were performed for cell lines of small cell carcinoma (TCYIK), squamous cell carcinoma (SiHa), and adenocarcinoma (HeLa). A total of 104 cases of formalin-fixed and paraffin-embedded specimens, 16 cases of cervical NEN and 88 cases of cervical non-NEN, were evaluated immunohistochemically for conventional neuroendocrine markers and INSM1. All processes without antigen retrieval were performed by an automated IHC system. The transcripts per million levels of INSM1 in RNA sequences were 1505 in TCYIK, 0 in SiHa, and HeLa. INSM1 immunoreactivity was shown only in the TCYIK. Immunohistochemical results showed that 15 cases of cervical NEN showed positive for INSM1; the positivity score of the tumor cell population and the stain strength for INSM1 were high. Two of the 88 cases of cervical non-NENs were positive for INSM1 in one case each of typical adenocarcinoma and squamous cell carcinoma. The sensitivity of INSM1 for cervical NEN was 94%; specificity, 98%; the positive predictive value, 88%; and the negative predictive value, 99%. INSM1 is an adjunctive diagnostic method with excellent specificity and sensitivity for diagnosing cervical NEN. Higher specificity can be obtained if morphological evaluation is also performed.

Validation of the 2023 FIGO staging system and its concordance with the JSGO guidelines in endometrial cancer: A multi‐institutional retrospective study in Japan

Abstract Aim To validate the prognostic accuracy of the 2023 FIGO staging system and assess its alignment with the Japan Society of Gynecologic Oncology (JSGO) guidelines for endometrial cancer treatment. Methods This retrospective cohort study included 1207 patients with endometrial cancer treated at four academic hospitals in Kanagawa, Japan, between 2018 and 2022. Patients were reclassified according to the FIGO 2023 system and the JSGO recurrence risk categories. Primary endpoints included stage migration, recurrence risk (RR), overall survival (OS), and concordance between the two classification systems. Results Under FIGO 2023, the stage distribution was: I, 741 (61.4%); II, 203 (16.8%); III, 149 (12.3%); and IV, 114 (9.4%), with stage migration observed in 36.3% of cases. The FIGO 2023 system provided clearer stratification of 3‐year RR than FIGO 2009, with the RR gap widening from 80.0% to 90.1%. Sixteen patients (3.5%) with stage IA3 were classified as high risk by JSGO criteria, while 14.4% of patients considered high risk by JSGO were downstaged under FIGO 2023. Additionally, 46 patients (19.6%) with FIGO stage IA were reclassified as intermediate risk owing to focal lymphovascular space invasion (LVSI). Substantial LVSI was significantly associated with recurrence and poor prognosis (3‐year OS rates: none 94.3%, focal 89.9%, and substantial 40.7%; p  < 0.05). Molecular testing was limited: p53 in 30.2%, MSI in 5.9%, and POLE was not available. Conclusions FIGO 2023 improves prognostic precision. Incorporating LVSI extent and molecular data may refine JSGO classifications and support more individualized adjuvant therapy strategies.