Objective:To investigate whether the immunohistochemical results of two markers PMS2 and MSH6 (2-MMR) could replace the four markers MLH1, PMS2, MSH2 and MSH6 (4-MMR) to detect mismatch repair deficient (dMMR) cancers.Methods:A retrospective analysis was conducted with summary of immunohistochemical data from 7 867 cases of gastric cancer, colorectal cancer, endometrial cancer, and other diseases in the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, from March 2018 to March 2023. The consistency of 2-MMR and 4-MMR results was examined. Microsatellite instability (MSI) and next-generation sequencing (NGS) were performed in patients with specific phenotypes.Results:The Cohen κ values of 2-MMR and 4-MMR in gastric cancer, colorectal cancer, endometrial cancer and other diseases were 0.88, 0.99, 0.88 and 1.00, respectively. The overall consistency, sensitivity and specificity were 0.97, 99.6%, and 100.0%, respectively. Both 2-MMR and 4-MMR could detect the difference between various clinicopathological features. 24 (0.3%) of the 7 867 patients were found to have a special phenotype of MMR, and 6 of them were selected for MSI and NGS molecular testing. MSI analysis showed MSI-H in all cases, while NGS found that 5 of them had MMR-related gene mutations and 1 had POLE p.S297F mutation.Conclusions:Compared with 4-MMR, 2-MMR has high consistency, specificity and sensitivity. The cases with special phenotype only account for extremely low proportion. Therefore, 4-MMR may be replaced with 2-MMR in dMMR screening.

Objective:To investigate the expression pattern of pan-TRK protein in colorectal cancers with NTRK gene fusion and mismatch repair deficient (dMMR) and to analyze its molecular pathological characteristics.Methods:A total of 117 dMMR colorectal cancers diagnosed in the Department of Pathology of Henan Provincial People′s Hospital, Zhengzhou, China from 2020 to 2023 were collected. Immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) and DNA/RNA-based next-generation sequencing (NGS) were used to detect pan-TRK protein expression and fusion partner genes in tumors, and to further explore the correlation between pan-TRK staining patterns and partner genes.Results:IHC and FISH were performed successfully in formalin-fixed paraffin-embedded tissues from 117 dMMR colorectal cancer patients. There were 15 (15/117, 12.8%) cases with positive pan-TRK, including 6 cases with strong staining in tumor cell membrane and cytoplasm, 2 cases with weakly granular staining in tumor cytoplasm, 2 cases with moderate dot-like staining in near 5% tumor cell nuclei, 1 case with moderately to strongly granular staining in the cytoplasm and membrane of tumor cells, 1 case with moderately to weakly granular staining in about 60% of the tumor cells, 1 case with strongly staining in about 1% of the tumor cells, 1 case with moderately to strongly staining in about 3% of the tumor cells and 1 case with diffuse, moderate para-nuclear dot-like and weakly perinuclear granular staining. NTRK1 gene disruption was detected in 6 cases (6/117, 5.1%) and consistent with diffusely strong expression of pan-TRK. Based on DNA/RNA NGS, it was further confirmed that the 6 cases with NTRK1 gene disruption all carried TPM3-NTRK1 fusion gene, and all had high microsatellite instability and high tumor mutation burden. No KRAS, NRAS, BRAF V600E or TP53 gene mutations were detected. Four patients carried frame shift mutations in RNF43. Other molecular changes included 3 cases with ROS1 gene mutation, 2 cases with BRAC, ALK, and EGFR gene mutations, 2 cases with ATM gene mutation, and 2 cases with KIT gene mutation. These were missense/frame shift mutations that were associated with no clinical significance. The nine pan-TRK-positive cases without NTRK gene fusion detected with DNA-based NGS were further confirmed with RNA-based NGS, and no NTRK gene fusion was found. The sensitivity and specificity of NTRK gene fusion detected using IHC were 100.0% and 92.5%, respectively. The sensitivity and specificity of diffusely strong membranous/cytoplasmic staining were both 100.0%.Conclusions:Pan-TRK protein has various expression patterns in dMMR colorectal cancer. Its diffusely strong expression is highly suggestive of NTRK1 gene fusion. TPM3-NTRK1 gene fusion is a common form of NTRK gene fusion in dMMR colorectal cancer.

With the in-depth promotion of precision medicine for breast cancer,pathological diagnosis has changed from traditional histological classification to a multidimensional system integrating morphology,immunohistochemistry and molecular target detection,and becoming a pivotal component in clinical treatment decision-making.Currently,the pathological diagnosis of breast cancer necessitates continuous optimization,including standardizing the interpretation of HER2-low expression,promoting the upfront detection for key targets,refining the structure of pathological reports,and further enhancing collaboration with clinical teams.These efforts aim to better meet the demands of precision treatment and provide patients with superior diagnostic support.Based on the clinical research progress and guideline consensus in recent years,this paper delves into the critical pathological hotspots in the clinical diagnosis and treatment of breast cancer,aiming to facilitate the implementation of standardized pathological diagnosis within the precision treatment framework.

HPV-independent vulvar intraepithelial neoplasia is rare and often develop vulvar squamous cell carci-noma in a short period of time or at the same time,and is the most common pre-lesion of vulvar squamous cell carcino-ma.HPV-independent vulvar intraepithelial neoplasia is significantly different in pathogenesis,pathological morpholo-gy,molecular characteristics,clinical treatment and prognosis.HPV-independent vulvar intraepithelial neoplasia is di-verse in morphology and can be divided into differentiated vulvar intraepithelial tumors and verrucous/acanthogenic in-traepithelial tumors/abnormal vulvar maturation,including TP53 gene mutant and wild type.HPV-independent vulvar intraepithelial neoplasia often occurs on the basis of chronic skin inflammation,and are easily confused with chronic dermatitis and squamous epithelial reactive hyperplasia.Correlation with the clinical,selecting appropriate immunohis-tochemical markers or molecular testing can help diagnose the disease.

Purpose To investigate the expression of bone sialoprotein(BSP)in the tissues and cells of endome-trial cancer(EC)and its effects on the proliferation and invasion of EC cells.Methods The expression of BSP was assessed by immunohistochemistry in 235 EC tissues and 88 normal endometrial tissues,and its correlation with clinico-pathological features was analyzed.Western blot was used to compare BSP levels between human endometrial carcinoma cell line(HHUA)and normal human endumetial epithelial cells(HEEC).BSP was knocked down in HHUA cells via transient transfection,and the cells were divided into blank control group and BSP-knockdown group.The effects of BSP knockdown on cell cycle,proliferation,migration,invasion,and apoptosis were evaluated using PI staining,CCK-8,scratch,Transwell,and Annexin V-FITC assays,respectively.Protein levels of TGF-β signaling pathway compo-nents were analyzed by Western blot.Results BSP expression was significantly higher in EC tissues than in normal endometrium(P＜0.001)and correlated with lymph node metastasis and advanced FIGO stage(P＜0.05).BSP pro-tein level was also significantly elevated in HHUA cells(2.455 8±0.008 9)compared to HEECs(1.571 2±0.005 4)(P＜0.01).After knockdown,compared with the control group,the proliferation index(74.4±3.33),migration rate(0.48±0.03),and invasion ability(0.36±0.11)of the cells were increased,and the apoptosis rate(25.97％)of the cells was increased(P＜0.05).Furthermore,the expression levels of TGF-β signaling pathway downstream proteins TGF-β1(0.290 4±0.002 3)、TGF-β2(0.292 9±0.001 6)、Smad2(0.469 3±0.001 1)、Smad3(0.247 0±0.001 7)、pAKT(0.382 1±0.001 9)、ATK(0.119 6±0.001 6)and MEK1(0.258 9±0.000 3)in the BSP-knockdown group of EC cells decreased(P＜0.01).Conclusion BSP is highly expressed in endometrial cancer and promotes cancer cell proliferation,invasion,and metastasis by activating the TGF-β signaling pathway.

Copper is one of the essential elements in the human body,playing various physiological roles.Maintai-ning copper homeostasis is crucial for health.Recent researches have uncovered that copper homeostasis imbalance is closely associated with the occurrence,progression,prognosis,and drug resistance of gynecological malignancies.The employment of copper and its complexes in antitumor therapy has emerged as a promising novel approach,attracting considerable research attention.Based on the relationship between copper homeostasis imbalance and gynecological tumors,this paper provides a concise review of the current status and progress of copper and its complexes in the treat-ment of gynecological tumors.

Purpose To analyze and compare the impact of incorporating molecular classification into the new FI-GO(2023)staging system for endometrial cancer(EC).Methods A retrospective analysis was conducted on 332 ca-ses of EC diagnosed and molecular subtyped by Department of Pathology Tianjin Central Hospital of Gynecology Obstet-rics in 2023.All cases were staged according to the FIGO(2023)staging criteria for EC.Results The median age of the 332 EC patients was 56 years(range:27-76 years).Molecular subtypes included 30 POLE mutation(POLE-mut),80 mismatch repair deficiency(MMRd),194 no specific molecular profile(NSMP),and 28 p53 abnormal(p53abn).Significant differences were observed among the four molecular subtypes regarding age,FIGO stage,patho-logical type,and lymph node metastasis rate(P＜0.05).However,no significant differences were found in the depth of myometrial invasion or lymphovascular space invasion.In the POLEmut group,19 cases(63.33％)were of non-ag-gressive histological types and 11(36.67％)were aggressive.After incorporating molecular subtyping,all 11 stage Ⅱ patients were downgraded to stage Ⅰ AmPOLEmut,increasing the proportion of stage Ⅰ patients from 62.07％to 100％.In the p53abn group,9 cases(32.14％)were non-aggressive and 19(67.86％)were aggressive.Molecular integra-tion led to the upstaging of 4 stage Ⅰ patients with myometrial invasion to stage Ⅱ Cmp53abn,increasing the proportion of stage Ⅱ patients from 34.61％to 50％.Conclusion Molecular subtypes p53abn and POLEmut are associated with distinct alterations in EC staging,specifically leading to tumor upstaging or downstaging.Our findings underscore the critical importance of comprehensive molecular subtyping in EC staging,as it refines prognostic risk stratification and provides valuable guidance for adjuvant treatment decisions.

Purpose This study aims to explore the effect of peroxisomal membrane protein 4(PXMP4)on the migration and invasion of cervical cancer(CC)cells,as well as the epithelial-mesenchymal transition(EMT)process.Methods Bioinformatics and immunohistochemical analysis were employed to examine the expression of PXMP4 in CC tissues and its correlation with clinical pathological characteristics.Western blot and RT-qPCR were used to detect the expression of PXMP4 in CC cells.CCK-8 assay,scratch healing assay,and Transwell invasion assay were utilized to assess the proliferation,migration,and invasion capabilities of CC cells.Western blot was conducted to measure the expression of N-cadherin,E-cadherin,vimentin,phosphorylated ERK(p-ERK),and total ERK proteins in cervical CC.Results The TCGA database showed that the mRNA expression level of PXMP4 was significantly elevated in non-paired CC tissues(P=0.000 29),while the GEO database showed that the mRNA expression level of PXMP4 was sig-nificantly elevated in paired CC tissues(P=0.02).Immunohistochemical analysis showed that PXMP4 was primarily localized in the cytoplasm and cell membrane,with a positive rate of 70.31％(45/64)in CC tissues,significantly higher than 29.69％(19/64)in adjacent tissues.Clinical pathological analysis found that PXMP4 expression was as-sociated with maximum tumor differentiation(P=0.000 328)and lymph node metastasis(P=0.000 226),but not with age(P=0.637)or tumor diameter(P=0.304).CCK-8 assay,wound healing assay,and Transwell invasion as-say demonstrated that interference with PXMP4 inhibited the proliferation,invasion,and migration of CC cells,while overexpression of PXMP4 promoted these processes.Western blot results indicated that interference with PXMP4 signif-icantly increased E-cadherin expression and decreased N-cadherin,vimentin,and p-ERK expression(P＜0.05).Conversely,overexpression of PXMP4 led to a significant decrease in E-cadherin and an increase in N-cadherin,vim-entin,and p-ERK expression(P＜0.05).Additionally,stimulation of CC cells with different concentrations of the U0126 inhibitor significantly increased E-cadherin expression and decreased N-cadherin,vimentin,and p-ERK expres-sion(P＜0.05).Conclusion PXMP4 is highly expressed in CC tissues and is closely related to tumor differentiation and lymph node metastasis.PXMP4 promotes the EMT process of CC cells through the phosphorylated ERK1/2 signa-ling pathway.

The safety management of dangerous chemicals has been identified as a critical component in China's 14th Five-Year Plan for emergency response planning.In recent years,the regulatory framework and standards,as well as the supervisory system for dangerous chemicals,have been continuously improved,with the managing entities strengthening risk identification in key areas.Currently,regulations on dangerous chemicals primarily focus on produc-tion,transportation,and warehousing industries.However,for the medical sector,particularly pathological laboratories which account for a significant portion of total hospital usage,there are no industry standards or expert consensuses on the standardized management and safe use of dangerous chemicals.This article reviews the classification,safety man-agement system,storage requirements,waste disposal,emergency response,and fire protection measures for dangerous chemicals in pathological laboratories.Based on the latest national standards and regulations,combined with the condi-tions of hospitals and pathological laboratories,this article aims to develop an expert consensus on the safe use and standardized management of dangerous chemicals in pathological laboratories,providing actionable guidance for their standardized construction and safety management.

Purpose To investigate the role of tumor-associated neutrophils(TANs)in the sternness characteris-tics of breast cancer cells.Methods Flow cytometry was used to identify and validate the successful generation of TANs.Breast cancer cell lines were co-cultured with TANs-conditioned supernatant,and their sphere-forming capacity was assessed.Western blot and reverse transcription-quantitative polymerase chain reaction(RT-qPCR)were used to detect the expression of stem cell-associated markers.In breast cancer clinical specimens,immunohistochemistry(IHC)was performed to quantify TANs infiltration and the expression of sternness-related markers.Correlations be-tween TANs infiltration and sternness marker expression,as well as their associations with clinicopathological features of breast cancer patients,were analyzed.Results Flow cytometry results demonstrated a significantly higher survival rate of TANs compared to normal neutrophils(NEUs)(P＜0.05).In vitro,TANs-derived supernatant significantly en-hanced the sphere-forming capacity of breast cancer cells compared to NEU-derived supernatant(P＜0.05).RT-qPCR analysis revealed that the mRNA expression levels of sternness-related markers such as CD133 and SOX9 in tumor cells was significantly increased after TANs supernatant co-cultured with breast cancer cells(P＜0.05).The results of western blot further confirmed that the protein expression levels of CD133 and SOX9 were markedly increased in the TANs supernatant group relative to the NEU supernatant group(P＜0.01).Immunophenotypic analysis showed that the infiltration density of CD66b+TANs in breast cancer tissues was positively correlated with the expression of CD133(r=0.429,P＜0.001)and SOX9(r=0.561,P＜0.001)in tumor cells.Prognostic and clinicopathological analy-ses indicated that patients in the high CD66b+TANs infiltration group,high CD133 expression group,and high SOX9 expression group had significantly shorter progression-free survival(PFS)than those in the corresponding low-expres-sion/infiltration groups(P＜0.05).Furthermore,the infiltration density of CD66b+TANs was significantly associated with patient age,histological grade,and lymph node metastasis status(all with P＜0.05).CD133 expression was cor-related with patient age,lymph node metastasis,and progesterone receptor(PR)status(all with P＜0.05),while SOX9 expression was associated with patient age and lymph node metastasis status(all with P＜0.05).Conclusion TANs can promote the acquisition and maintenance of sternness characteristics in breast cancer cells.These findings may provide novel insights into the development of neutrophil-targeted immunotherapeutic strategies for breast cancer.