Objective:To explore the consistency of claudin 18.2 immunohistochemistry (IHC) using 4 different clone antibodies in gastric adenocarcinoma.Methods:A total of 226 gastric adenocarcinomas diagnosed and treated at the Drum Tower Hospital Affiliated to Nanjing University Medical College between January 2022 to March 2023 were included in this study. The cohort consisted of 165 males and 61 females, with a mean age of (61.3±12.1) years. Tumor tissues from radical resection specimens were collected for tissue microarrays. IHC detection of claudin 18.2 was performed using the EnVision method, utilizing 4 clones of antibody: OTIR157B5, 43-14A, EPR19202 and D313D22. The results were interpreted based on both the intensity of staining on tumor cell membranes and the percentage of positive tumor cells relative to the total tumor cells.Results:The positive cutoff value was set as moderately to strongly linear membrane staining in ≥75% of all viable invasive tumor cells, and clone OTIR157B5 demonstrated the highest positive expression rate at 52.2% (118/226). Additionally, the clones OTIR157B5, 43-14A, and EPR19202 were consistently and strongly positive, with all agreement rates of Cohen κ exceeding 0.8. In gastric adenocarcinoma and its three Lauren subtypes, OTIR157B5 exhibited clear membranous localization.Conclusions:Clone OTIR157B5 of claudin 18.2 antibody shows the highest rate of moderately to strongly linear membrane-positive staining, accounting for ≥75% of all viable invasive tumor cells, and clones 43-14A and EPR19202 show strong consistency and high sensitivity.

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 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 explore the consistency of claudin 18.2 immunohistochemistry (IHC) using 4 different clone antibodies in gastric adenocarcinoma.Methods:A total of 226 gastric adenocarcinomas diagnosed and treated at the Drum Tower Hospital Affiliated to Nanjing University Medical College between January 2022 to March 2023 were included in this study. The cohort consisted of 165 males and 61 females, with a mean age of (61.3±12.1) years. Tumor tissues from radical resection specimens were collected for tissue microarrays. IHC detection of claudin 18.2 was performed using the EnVision method, utilizing 4 clones of antibody: OTIR157B5, 43-14A, EPR19202 and D313D22. The results were interpreted based on both the intensity of staining on tumor cell membranes and the percentage of positive tumor cells relative to the total tumor cells.Results:The positive cutoff value was set as moderately to strongly linear membrane staining in ≥75% of all viable invasive tumor cells, and clone OTIR157B5 demonstrated the highest positive expression rate at 52.2% (118/226). Additionally, the clones OTIR157B5, 43-14A, and EPR19202 were consistently and strongly positive, with all agreement rates of Cohen κ exceeding 0.8. In gastric adenocarcinoma and its three Lauren subtypes, OTIR157B5 exhibited clear membranous localization.Conclusions:Clone OTIR157B5 of claudin 18.2 antibody shows the highest rate of moderately to strongly linear membrane-positive staining, accounting for ≥75% of all viable invasive tumor cells, and clones 43-14A and EPR19202 show strong consistency and high sensitivity.

Objective:To investigate the diagnostic value of preferentially expressed antigen in melanoma (PRAME) immunohistochemical staining in differential diagnosis of primary endometrial and endocervical adenocarcinomas.Methods:Eighty‐seven cases of endometrial adenocarcinoma and sixty-three cases of cervical adenocarcinoma were collected from May 2018 to November 2023 in the Department of Pathology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School and all the cases were subject to PRAME immunohistochemical staining. The difference of PRAME expression between endometrial and endocervical adenocarcinomas was analyzed.Results:In 87 cases of endometrial adenocarcinoma, patients′ age ranged from 35 to 71 years (average 59 years, median 59 years); in 63 cases of cervical adenocarcinoma patients′ age ranged from 28 to 80 years (average 49 years, median 47 years). Seventy‐eight cases (78/87, 89.7%) of endometrial adenocarcinoma; 2 cases (2/63, 3.2%) of cervical adenocarcinoma showed positive PRAME staining, and both cases of cervical adenocarcinoma were clear cell carcinoma. The sensitivity and specificity of PRAME in distinguishing between endometrial and cervical adenocarcinoma in the cohort were 89.7% and 96.8%, while those in differentiating non-clear cell carcinoma of the uterus from that of the cervix reached up to 91% and 100%, respectively.Conclusions:Immunohistochemical staining for PRAME demonstrates statistically significant differences between endometrial and cervical carcinomas, making it a useful auxiliary diagnostic marker for differentiating cervical and endometrial adenocarcinoma, especially non-clear cell carcinoma.

Purpose The purpose of this study was to in-vestigate programmed death ligand-1(PD-L1)expression in gastric adenocarcinoma(GAC)patients and the consistency of immunohistochemical(IHC)detection of four different clones of PD-L1 antibodies,so as to provide reference for the gradual standardization of PD-L1 IHC detection in gastric adenocarcino-ma and subsequent clinical studies.Methods This study col-lected surgically resected and pathologically confirmed specimens from 286 gastric adenocarcinoma patients,and specimens were stained with four antibodies:PD-L1 22C3,SP263,E1L3N and SP142.The consistency of the antibodies was statistically ana-lyzed under different critical values using two scoring criteria:comprehensive positive score(CPS)and tumor proportion score(TPS).Results Regardless of the TPS and CPS cut-off val-ues,the positive rate of 22C3 was the highest among the four an-tibodies.Consistency analysis showed that E1L3N had good con-sistency with SP142(κ=0.612)and SP263(κ=0.660)only when the cut-off value of CPS positive was 1.In addition,the consistency between the other antibodies was only moderate or poor.Conclusion The four PD-L1 antibodies exhibited incon-sistent concordance across various TPS and CPS positive thresh-olds,so it is not recommended to exchange reagents during clini-cal testing of GAC and the test results shall be documented in accordance with the specification.

Purpose To investigate the clinicopathological characteristics,diagnosis,and differential diagnosis of invasive mucinous adenocarcinoma(IMA)and mixed invasive mucinous and non-mucinous adenocarcinoma(mIMA).Methods The clinical data were collected in 36 patients with primary IMA and 17 patients with mIMA,and the expression of TTF-1,CK7,CK20,SATB2,CDX2,EGFR,HNF4a,etc.was detected by immunohistochemical EnVision two-step method.The Sanger se-quencing and the FISH were used for KRAS mutation and NRG1 gene rearrangement detection.The clinicopathological character-istics were analyzed with review of relevant literature.Results There were 9 cases(25.0％)and 3(8.3％)cases of papillary and micropapillary structures in IMA,while 13 cases(76.5％)(P＜0.001)and 9 cases(52.9％)(P=0.001)were present in mIMA.There were 5 cases(13.9％)of high nuclear grade of IMA and 10 cases(58.8％)of high nuclear grade of mIMA(P=0.002).TTF-1 had a positive rate of 37.5％in IMA,but 60.0％and 80.0％in the mucinous adenocarcinoma and non-mucinous adenocarcinoma components of mIMA(P=0.021),respectively.The positive rates of CK7,CK20,and CDX2 in IMA were 90.6％,21.9％,and 9.4％,and the positive rates in mucinous adenocarcinoma and non-mucinous adenocarcinoma components of mIMA were 100％,20％,20％and 100％,6.7％,6.7％,respectively and no SATB2 expression was found in all cases.There was no significant difference in the expres-sion of total EGFR and two EGFR mutation-specific antibodies(L858R,DEL19)between IMA and mIMA.There were 3 cases of mucinous adenocarcinoma with L858R positive in mIMA,and 2 of them were negative for non-mueinous adenocarcinoma.In another case,the non-mueinous adenocarcinoma component of mIMA expressed DEL19,but the mucinous adenocarcinoma component was not expressed.The positive rate of HNF4a in IMA was 72.0％(18/25),and those of HNF4a in mucinous adenocarcinoma and non-mucinous adenocarcinoma in mIMA were 41.7％(5/12)and 33.3％(4/12),respectively(P=0.048).KRAS gene sequencing was carried out in 19 cases of IMA,among which 9 cases(47.4％)had mutations,G12D and G12V were most commonly detected,and 4 cases of mIMA were sequenced,but none of them showed KRAS mutations.FISH detection showed that 2 cases(7.1％)IMAs had NRG1 translocation rearrangement.Conclusion Pulmonary mIMA is more aggressive than IMA.For example,mIMA has significantly more papillary structure,micropapillary structure,and high nu-clear grade cases than IMA.The differences in immunohisto-chemical expression and KRAS mutation between the two are sta-tistically significant.

Objective: To investigate the association between the whole blood riboflavin level and the occurrence, development and prognosis of esophageal squamous cell carcinoma (ESCC) in China. Methods: From March 2014 to September 2018, ESCC patients from three hospitals (the Affiliated Hospital of Medical College of Shantou University, Shantou Central Hospital in Southern Chaoshan area and First Affiliated Hospital of Zhengzhou University in Northern Taihang Mountain) were selected as a case group; non-esophageal patients who had a physical examination were selected as a control group. The case and control group were paired by age (±5 years) and a 1:1 ration. A total of 1 528 subjects were enrolled including 764 patients in the case group and 764 patients in the control group. About 3-5 ml venous blood samples were collected, and the erythrocyte glutathione reductase activity coefficient (GRAC) was measured to assess the whole blood riboflavin level. A multivariate conditional logistic regression model was used to analyze the association between the GRAC and the risk of ESCC. The association between the GRAC and the prognosis of ESCC was analyzed by using Cox proportional risk regression model based on 288 patients with complete survival data. They were divided into two groups, the high GRAC group (GRAC≥7.87) group and the low GRAC group (GRAC<7.87) according to the strongest correlation between the total survival time, survival outcome and GRAC (GRAC=7.87). Results: Among the 1 528 patients, 958 patients were from Southern Chaoshan area, including 479 patients in the case group with an average age about (59.90±9.34) years and 479 patients in the control group with an average age about (59.55±8.77) years. Other 570 patients were from Northern Taihang Mountain area, including 285 patients in the case group with an average age (58.39±5.19) years and 285 patients in the control group with an average age about (58.74±4.57) years. The multivariate conditional logistic regression showed that the OR (95%CI) of the GRAC and the risk of ESCC was 1.009 (0.998-1.019). The Cox proportional hazard regression model analysis showed that the HR (95%CI) of the high GRAC group was 1.712 (1.034-2.824) compared with the low GRAC group in the 50-70 years group. Conclusion The whole blood riboflavin level might not be associated with the occurrence of ESCC. The high whole blood riboflavin level would be more beneficial to the prognosis of ESCC patients aged 50-70 years.