Clinicopathological and prognostic significance of immunophenotypic characterization of endocervical adenocarcinoma using CLDN18, CDH17, and PAX8 in association with HPV status

Cell lineage-specific immunohistochemical markers in biliary intraepithelial neoplasia: Implications for subclassification and grading

Biliary intraepithelial neoplasia (BilIN), a precursor to cholangiocarcinoma, is categorized into low- and high-grade based on histological characteristics. Although gastric, intestinal, and biliary phenotypes of BilIN have been identified, detailed analyses of their immunophenotypic profiles using cell lineage-specific markers remain limited. This study aimed to define the immunohistochemical profiles of BilIN lesions, subclassify them based on their immunophenotypes, and correlate these profiles with histological grades. We examined 77 BilIN lesions from extrahepatic bile ducts, including 30 low- and 47 high-grade lesions, using immunohistochemical staining for gastric (claudin-18, MUC5AC), intestinal (cadherin-17, glycoprotein A33), and biliary (carbohydrate sulfotransferase 4) markers, along with progression markers (S100P, IMP3). Expression levels were semiquantitatively scored and correlated with histopathological features. BilIN lesions were classified into four immunophenotypes: gastric (G-type), intestinal (I-type), gastrointestinal (GI-type), and biliary (B-type). Low-grade lesions comprised G- (33.3 %), GI- (40 %), I- (13.3 %), and B-types (13.3 %), while high-grade lesions included G- (40.4 %), GI- (29.8 %), I- (21.3 %), and B-types (8.5 %). In low-grade BilIN, G-type lesions corresponded to gastric mucous cells, I-type to intestinal epithelial cells, and B-type to bile duct epithelial cells, while most GI-type lesions exhibited mixed G- and I-type components. High-grade BilIN differentiation based solely on histological characteristics was challenging to delineate due to overlapping features among I-, GI-, and B-type cells. S100P and IMP3 expression levels were significantly elevated in high-grade lesions, particularly within the I+B-type BilIN group, with no notable differences in G- or GI-type BilIN. Immunophenotypic profiling with lineage-specific markers effectively subclassified BilIN, enhancing the understanding of its histogenesis and progression.

Extensive Pathologic Invasion and Prognostic Implication of Gastric-Type Cervical Adenocarcinoma: A Comparative Analysis With Human Papillomavirus-Associated Adenocarcinoma

Gastric-type adenocarcinoma (GAS) is the most common subtype of human papillomavirus (HPV)-independent cervical adenocarcinomas and is associated with a poor prognosis. We used a gross morphologic classification system and imaging analysis to compare the clinicopathological features of GAS and HPV-associated adenocarcinoma (HPVA) and identify factors contributing to the poor prognosis of GAS. This retrospective 2-center study analyzed 33 patients with GAS and 70 with HPVA (stages IB-IVB) who underwent surgery between 1997 and 2023. GAS had a higher rate of positive surgical margins (21.2% vs. 0%, respectively, P <0.001) and unclear tumor boundaries on gross morphologic findings (47.8% vs. 8.8%, respectively, P <0.001). Discrepancies between clinical and pathologic T classifications were more common in GAS, leading to frequent upstaging (51.5% vs. 28.6%, respectively, P =0.029). Imaging analysis revealed that GAS was associated with a smaller median tumor cell area (19.8% vs. 55.7%, respectively, P <0.001), which was significantly correlated with unclear tumor boundaries. Perineural invasion (PNI) was significantly more frequent in GAS (69.7% vs. 10.0%, respectively, P <0.001). A Kaplan-Meier analysis showed that patients with PNI had significantly poorer overall survival ( P <0.001). A Cox multivariate analysis identified an advanced pathologic stage, positive peritoneal cytology, and positive surgical margins as independent risk factors. The present results indicate that GAS has a unique "stealth" invasion pattern, possibly caused by low tumor density, leading to undetectable tumor boundaries and positive surgical margins. This suggests a greater risk of incomplete resection than HPVA, leading to a poorer prognosis.

Prognostic role of claudin-18.2 in intrahepatic cholangiocarcinoma

Claudins are key components of tight junctions, essential for maintaining cellular adhesion, regulating intercellular molecule transport, and preserving cell polarity. Altered claudin expression can lead to tight junction dysfunction, potentially disrupting signaling pathways and contributing to the development of epithelial cancers. This study aims to explore the understudied role of CLDN18.2 in intrahepatic cholangiocarcinoma and its relationship with clinical outcomes. We analyzed tissue samples from 182 patients who underwent curative surgery for intrahepatic cholangiocarcinoma. Our research examined the relationship between CLDN18.2 expression and various clinical factors, including patient characteristics, pathological findings, and survival metrics such as overall survival (OS), disease-free survival (DFS), metastasis-free survival (MeFS), and local recurrence-free survival (LRFS). Overexpression of CLDN18.2 showed significant associations with R1 resection (p = 0.032) and advanced T stage (p = 0.043). Univariate analysis revealed that high CLDN18.2 expression was correlated with poorer OS (p = 0.0002), DFS (p < 0.0001), LRFS (p < 0.0001), and MeFS (p < 0.0001). Multivariate analysis further confirmed that high CLDN18.2 expression was independently associated with worse OS (p = 0.015), DFS (p < 0.001), LRFS (p < 0.001), and MeFS (p < 0.001). Overexpression of CLDN18.2 was associated with unfavorable clinical prognosis and adverse pathological features in intrahepatic cholangiocarcinoma. These findings suggest that CLDN18.2 could serve as a potential prognostic biomarker for intrahepatic cholangiocarcinoma.

Multiple Nabothian Cysts and Tunnel Clusters Clinically Mimicking Lobular Endocervical Glandular Hyperplasia: A Case Report

This report describes a 48-year-old woman who presented with multiple cystic lesions in the uterine cervix. Magnetic resonance imaging (MRI) showed multiple large and small cysts in the uterine cervix, which raised lobular endocervical glandular hyperplasia (LEGH) as a differential diagnosis, because a cosmotic and microcystic pattern characteristic of LEGH might be suggested. However, pathological examination of the conization specimen revealed the simultaneous occurrence of superficial and deep Nabothian cysts (NCs) and tunnel clusters (TCs), without evidence of LEGH. LEGH is a potential precursor lesion to gastric-type adenocarcinoma (GAC) and should be distinguished from NCs and TCs, which do not typically require follow-up. This case highlights the challenges in the clinicoradiological differentiation between benign cervical lesions and LEGH. Clinicians and pathologists should be aware of the possibility of coexisting NCs and TCs mimicking LEGH in imaging studies.

Expression profiles of cadherin 17 and claudin 18.2 in comparison with peptide hormonal expression in pancreatic neuroendocrine tumours: Implications for targeted immunotherapy

Cadherin 17 (CDH17) and claudin 18.2 (CLDN18.2) are highly selective markers of intestinal and gastric lineages and are expressed in adenocarcinomas of various organs. They have also been identified as potential targets for immunotherapy. Expression of CDH17 and CLDN18.2 has been observed in a subset of pancreatic neuroendocrine tumours (PanNETs). This study investigates the immunohistochemical expression of CDH17 and CLDN18 in PanNETs in comparison with hormonal expression profiles to provide baseline data for determining candidate indications for targeted therapy with CDH17 and CLDN18.2 in PanNETs, including insulinomas (n = 22), glucagonomas (n = 13), gastrinomas (n = 3), serotoninomas (n = 2) and PanNETs not otherwise specified (NOS) (n = 17). In the normal pancreas, CDH17 was expressed in the lateral membrane of ducts and some islet cells, whereas CLDN18 was occasionally expressed in the intercalated ducts and centroacinar cells. In PanNETs, CDH17 and CLDN18 was detected by membranous staining. CDH17 expression was observed in 10 to 17 (58.8 %) PanNETs NOS, 3 of 13 (23.1 %) glucagonomas, 1 of 3 (33.3 %,) gastrinomas, 1 of 2 (50 %) serotoninomas, and none of the insulinomas. According to predefined criteria, 7 of 17 (41.2 %) PanNETs NOS, 1 of 3 (33.3 %) gastrinomas, and 1 of 2 (50 %) serotoninomas were classified as CDH17-positive. There were no significant differences in clinicopathological features between CDH17-positive and CDH17-negative PanNETs, except for a higher tumour grade in the former (p<0.05). For CLDN18, expression was noted in 2 out of 3 (66.7 %) gastrinomas, one with focal staining and the other with diffuse staining. One of three (33.3 %) gastrinomas was classified as CLDN18-positive using predefined criteria. These findings suggest that a particular subset of PanNETs, including PanNET NOS, gastrinoma, and serotoninoma, may be potential candidates for CDH17-targeted immunotherapy. Additionally, gastrinoma may be a potential candidate for immunotherapy targeting CLDN18.2.

Gastric-type adenocarcinoma of the uterine cervix: clinical features and future directions

The concept of gastric-type mucinous carcinoma of the uterine cervix (GAS) has been accepted worldwide because of its aggressive clinical behaviour and the absence of high-risk human papilloma virus infection. The World Health Organization (WHO) 2020 classification divides cervical tumours into two categories: human papilloma virus-associated and human papilloma virus-independent. Hence, GAS is now classified as an human papilloma virus-independent gastric type. Because clinical studies have reported that GAS is refractory to conventional treatments such as chemotherapy and radiotherapy, especially at an advanced stage, and has aggressive features with widespread dissemination to unusual sites, such as the omentum, peritoneum and distant organs, it is urgent to establish new treatment strategies by comparing the molecular profiles of human papilloma virus-associated adenocarcinomas. A series of genetic mutations characteristic to GAS encourage the development of future treatment strategies such as targeted therapy and immunotherapy.

Cadherin-17 (CDH17) expression in human cancer: A tissue microarray study on 18,131 tumors

Cadherin-17 (CDH17) is a membranous cell adhesion protein predominantly expressed in intestinal epithelial cells. CDH17 is therefore considered a possible diagnostic and therapeutic target. This study was to comprehensively determine the expression of CDH17 in cancer and to further assess the diagnostic utility of CDH17 immunohistochemistry (IHC). A tissue microarray containing 14,948 interpretable samples from 150 different tumor types and subtypes as well as 76 different normal tissue types was analyzed by IHC. In normal tissues, a membranous CDH17 staining was predominantly seen in the epithelium of the intestine and pancreatic excretory ducts. In tumors, 53 of 150 analyzed categories showed CDH17 positivity including 26 categories with at least one strongly positive case. CDH17 positivity was most common in epithelial and neuroendocrine colorectal neoplasms (50.0%-100%), other gastrointestinal adenocarcinomas (42.7%-61.6%), mucinous ovarian cancer (61.1%), pancreatic acinar cell carcinoma (28.6%), cervical adenocarcinoma (52.6%), bilio-pancreatic adenocarcinomas (40.5-69.8%), and other neuroendocrine neoplasms (5.6%-100%). OnIy 9.9% of 182 pulmonary adenocarcinomas were CDH17 positive. In colorectal adenocarcinomas, reduced CDH17 staining was linked to high pT (p = 0.0147), nodal metastasis (p = 0.0041), V1 (p = 0.0025), L1 (p = 0.0054), location in the right colon (p = 0.0033), and microsatellite instability (p < 0.0001). The CDH17 expression level was unrelated to tumor phenotype in gastric and pancreatic cancer. In summary, our comprehensive overview on CDH17 expression in human tumors identified various tumor entities that might often benefit from anti-CDH17 therapies and suggest utility of CDH17 IHC for the distinction of metastatic gastrointestinal or bilio-pancreatic adenocarcinomas (often positive) from primary pulmonary adenocarcinomas (mostly negative).

Integration and viral oncogene expression of human papillomavirus type 16 in oropharyngeal squamous cell carcinoma and gastric cancer

Persistent high-risk human papillomavirus (HR-HPV) infections cause cervical cancer and a fraction of head and neck cancer. To investigate whether HR-HPV infection might be also involved in the development of gastric cancer (GC), we developed a platform utilizing a rolling circle amplification (RCA)-based nested L1 polymerase chain reaction with Sanger sequencing to genotype the HPV DNA in cancer tissues of 361 GC and 89 oropharyngeal squamous cell carcinomas (OPSCC). HPV transcriptional activity was determined by E6/E7 mRNA expression and a 3' rapid amplification of cDNA ends was performed to identify HPV integration and expression of virus-host fusion transcripts. Ten of 361 GC, 2 of 89 OPSCC, and 1 of 22 normal adjacent tissues were HPV L1 DNA-positive. Five of the 10 HPV-positive GC were genotyped as HPV16 by sequencing and 1 of 2 GC with RCA/nested HPV16 E6/E7 DNA detection exhibited HPV16 E6/E7 mRNA. Two OPSCC displayed HPV16 L1 DNA and E6/E7 mRNA, of which 1 OPSCC tissue showed virus-host RNA fusion transcripts from an intron region of KIAA0825 gene. Together, our data reveal viral oncogene expression and/or integration in GC and OPSCC and a possible etiology role of HPV infections in gastric carcinogenesis.

Targeting CLDN18.2 in cancers of the gastrointestinal tract: New drugs and new indications

Cancers of the gastrointestinal (GI) tract greatly contribute to the global cancer burden and cancer-related death. Claudin-18.2(CLDN18.2), a transmembrane protein, is a major component of tight junctions and plays an important role in the maintenance of barrier function. Its characteristic widespread expression in tumour tissues and its exposed extracellular loops make it an ideal target for researchers to develop targeted strategies and immunotherapies for cancers of the GI tract. In the present review, we focus on the expression pattern of CLDN18.2 and its clinical significance in GI cancer. We also discuss the tumour-promoting and/or tumour-inhibiting functions of CLDN18.2, the mechanisms regulating its expression, and the current progress regarding the development of drugs targeting CLDN18.2 in clinical research.

Current status and molecular biology of human papillomavirus-independent gastric-type adenocarcinoma of the cervix

This article reviews the findings of clinical studies on gastric-type adenocarcinoma of the cervix to date, outline the molecular biological features identified in recent studies, and discusses the future therapeutic strategies. Gastric-type adenocarcinoma of the cervix is a new classification in the World Health Organization 2014 classification. The World Health Organization 2020 classification further divides cervical tumors into two categories: human papillomavirus-associated and human papillomavirus-independent. Thus, gastric-type adenocarcinoma of the cervix is now classified as a human papillomavirus-independent gastric type. Clinical studies have reported that gastric adenocarcinoma of the cervix is refractory to conventional chemotherapy and radiotherapy, and it is desirable to elucidate its molecular biological mechanism. A series of gene mutations characteristic to the gastric-type adenocarcinoma of the cervix encourage the development of future treatment strategies.

Infection status and survival impact of high-risk human papillomavirus in cervical adenocarcinomas: A systematic review and meta-analysis

OBJECTIVE

Cervical adenocarcinoma (CAC) comprises a heterogeneous group of tumors that are not universally associated with HPV infection. As has been shown in other organs, it is becoming increasingly apparent that HPV status significantly affects the prognosis of adenocarcinoma. We conducted a systematic review and meta-analysis to investigate the infection status of high-risk Human papillomavirus (hrHPV) in CAC and evaluate its impact on the survival of patients.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials.gov were searched from inception to May 1st, 2022. Data on HPV infection status and survival outcomes were evaluated using STATA 16.0.

RESULTS

Seventy-one studies with 11,278 participants were included in HPV infection analysis and eight studies with 1099 participants were included in prognosis analysis. The HPV infection rate (including high-risk and low-risk) and hrHPV infection rate in CAC were 75% (95% CI 0.70-0.80, 6978 participants) and 75% (95% CI 0.70-0.81, 4906 participants), respectively. HPV-16 and -18 were the most common HPVs in CAC, with pooled infection rates of 37% (95% CI 0.33-0.41, 7848 participants) and 34% (95% CI 0.30-0.38, 7730 participants), respectively. hrHPV infection was associated with better overall survival (HR 0.23, 95% CI 0.11-0.47, 1013 participants), better disease-free survival (HR 0.18, 95% CI 0.07-0.43, 292 participants), better progression-free survival (HR 0.20, 95% CI 0.08-0.47, 271 participants) and less recurrence (RR 0.30, 95% CI 0.07-0.43, 181 participants).

CONCLUSION

HPV infection rates were high in CAC. HPV-16 and -18 had the highest infection rates in CAC. However, hrHPV infection was associated with better survival and less recurrence. Future studies should clarify the relationship between hrHPV infection and other prognostic factors and make reasonable treatment strategies for CAC with different HPV status.

PROTOCOL REGISTRATION

CRD42022319390.

Membranous and nuclear staining of CLDN18 in HPV-independent and HPV-associated endocervical adenocarcinomas

OBJECTIVES

A classification system for endocervical adenocarcinoma (ECA) based on high-risk human papillomavirus (HPV) status has been established; however, the immunohistochemical markers distinguishing HPV-independent and HPV-associated ECAs have not been fully described. Here, we aimed to characterize ECA immunopathological features.

METHODS

We evaluated the immunohistochemical profile of CLDN18, CDX2, PAX8, p16, p53, and CEA in 60 ECAs comprising 10 HPV-independent ECAs and 50 HPV-associated ECAs. Both the membranous and nuclear expression levels of CLDN18 were analyzed.

RESULTS

Membranous CLDN18 (CLDN18 [M]) was found to be expressed in the mucinous epithelium of all HPV-independent ECAs, including eight gastric-type ECAs (G-ECAs), one endometrioid ECA, and one clear cell ECA, but no nuclear CLDN18 (CLDN18 [N]) expression was detected in HPV-independent ECAs. Among HPV-associated ECAs, CLDN18 (M) expression levels in intestinal-type (I-ECAs) and usual-type ECAs (U-ECAs) were significantly different from those in invasive stratified mucin-producing (iSMILE) carcinomas (p = 0.036). Positive CLDN18 (M) staining was present in 55.6% (5/9) of intestinal-type and 39.4% (13/33) of usual-type ECAs and was not present in iSMILE ECAs. Silva pattern C cancers expressed higher levels of CLDN18 (M) than Silva pattern A and B cancers (p = 0.004), whereas the CLDN18 (N) expression levels in cancers showing Silva pattern A were significantly higher than those in cancers exhibiting Silva patterns B and C (p < 0.001).

CONCLUSION

Membranous CLDN18 is expressed in ECAs and is particularly frequently expressed in HPV-independent ECAs, and membranous CLDN18 expression has potential as a therapeutic target. Nuclear staining of CLDN18 is a new immunohistochemical marker for diagnosing Silva pattern A HPV-associated ECAs and is associated with a good prognosis. Further studies should investigate the therapeutic and prognostic significance of membranous and nuclear CLDN18 expression and develop a related test that can be implemented in the clinical evaluation of ECAs.