Objective: To explore the concordance and causes of different mismatch repair (MMR) and microsatellite instability (MSI) detection results in endometrial carcinoma (EC) molecular typing. Methods: A total of 214 EC patients diagnosed from January 2021 to April 2023 were selected at the Department of Pathology, Peking University Third Hospital. The immunohistochemistry (IHC) results of MMR protein were reviewed. Tumor specific somatic mutations, MMR germline mutations, microsatellite scores and tumor mutation burden (TMB) were detected by next-generation sequencing (NGS) with multi-gene panel. Methylation-specific PCR was used to detect the methylation status of MLH1 gene promoter in cases with deficient MLH1 protein expression. In cases with discrepant results between MMR-IHC and MSI-NGS, the MSI status was detected again by PCR (MSI-PCR), and the molecular typing was determined by combining the results of TMB and MLH1 gene promoter methylation. Results: (1) In this study, there were 22 cases of POLE gene mutation subtype, 55 cases of mismatch repair deficient (MMR-d) subtype, 29 cases of p53 abnormal subtype, and 108 cases of no specific molecular profile (NSMP). The median age at diagnosis of MMR-d subtype (54 years old) and the proportion of aggressive histological types (40.0%, 22/55) were higher than those of NSMP subtype [50 years old and 12.0% (13/108) respectively; all P<0.05]. (2) Among 214 patients, MMR-IHC test showed that 153 patients were mismatch repair proficient (MMR-p), 49 patients were MMR-d, and 12 patients were difficult to evaluate directly. MSI-NGS showed that 164 patients were microsatellite stable (MSS; equal to MMR-p), 48 patients were high microsatellite instability (MSI-H; equal to MMR-d), and 2 patients had no MSI-NGS results because the effective sequencing depth did not meet the quality control. The overall concordance between MMR-IHC and MSI-NGS was 94.3% (200/212). All the 12 discrepant cases were MMR-d or subclonal loss of MMR protein by IHC, but MSS by NGS. Among them, 10 cases were loss or subclonal loss of MLH1 and (or) PMS2 protein. Three discrepant cases were classified as POLE gene mutation subtype. In the remaining 9 cases, 5 cases and 3 cases were confirmed as MSI-H and low microsatellite instability (MSI-L) respectively by MSI-PCR, 6 cases were detected as MLH1 gene promoter methylation and 7 cases demonstrated high TMB (>10 mutations/Mb). These 9 cases were classified as MMR-d EC. (3) Lynch syndrome was diagnosed in 27.3% (15/55) of all 55 MMR-d EC cases, and the TMB of EC with MSH2 and (or) MSH6 protein loss or associated with Lynch syndrome [(71.0±26.2) and (71.5±20.1) mutations/Mb respectively] were significantly higher than those of EC with MLH1 and (or) PMS2 loss or sporadic MMR-d EC [(38.2±19.1) and (41.9±24.3) mutations/Mb respectively, all P<0.01]. The top 10 most frequently mutated genes in MMR-d EC were PTEN (85.5%, 47/55), ARID1A (80.0%, 44/55), PIK3CA (69.1%, 38/55), KMT2B (60.0%, 33/55), CTCF (45.5%, 25/55), RNF43 (40.0%, 22/55), KRAS (36.4%, 20/55), CREBBP (34.5%, 19/55), LRP1B (32.7%, 18/55) and BRCA2 (32.7%, 18/55). Concurrent PTEN, ARID1A and PIK3CA gene mutations were found in 50.9% (28/55) of MMR-d EC patients. Conclusions: The concordance of MMR-IHC and MSI-NGS in EC is relatively high.The discordance in a few MMR-d EC are mostly found in cases with MLH1 and (or) PMS2 protein loss or MMR protein subclonal staining caused by MLH1 gene promoter hypermethylation. In order to provide accurate molecular typing for EC patients, MLH1 gene methylation, MSI-PCR, MMR gene germline mutation and TMB should be combined to comprehensively evaluate MMR and MSI status.
Female ; Humans ; Middle Aged ; Class I Phosphatidylinositol 3-Kinases/metabolism* ; Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis* ; DNA Mismatch Repair/genetics* ; Endometrial Neoplasms/pathology* ; Microsatellite Instability ; Mismatch Repair Endonuclease PMS2/genetics* ; Molecular Typing

Objective: To investigate the molecular classification and clinicopathological features of endometrial carcinoma(EC). Methods: One hundred cases of EC diagnosed in the Department of Pathology, Tianjin Central Hospital of Gynecology and Obstetrics from November 2020 to November 2021 were selected. Sanger sequencing and immunohistochemical staining were used for molecular classification according to the 5th WHO classification. The clinicopathological characteristics of each molecular subtype was analyzed. Results: The 100 EC patients had a mean age of 53 years (range 26 to 72 years). There were 10 cases of POLE mutation (POLE mut), including two cases (2/10) of "binary-classifier" EC, two cases (2/10) of FIGO Grade 3 endometrioid endometrial carcinoma (G3-EEC), and three cases (3/10) of other high-grade subtypes. There were 38 cases of mismatch repair deficiency (dMMR), including one case (1/38, 2.6%) of "binary-classifier" EC and 36 cases (36/38, 94.7%) were EEC. Twenty-one cases (21/38, 55.3%) showed simultaneous loss of expression of MLH1 and PMS2, and 20 cases (20/21, 95.2%) were positive for MLH1 methylation, indicating that they were sporadic EC. Six patients (6/38, 15.8%) were tested for germline detection of Lynch syndrome (LS) related genes, and one patient was LS-related EC. There were 44 cases of non-specific molecular profile (NSMP), including 34 cases (34/44, 77.3%) of G1-2 EEC and seven cases (7/44, 15.9%) of G3-EEC. There were eight cases of p53 abnormality (p53 abn), including four cases (4/8) of G3-EEC, two cases (2/8) of other high-grade subtypes, and one patient had hereditary breast cancer and ovarian cancer syndrome. Conclusions: Correct interpretation of POLE mutation, MMR and p53 immunohistochemistry is the key of molecular classification. The interpretation must strictly follow standard diagnostic procedures and specifications to ensure the accuracy of molecular classification.
Adult ; Aged ; Carcinoma, Endometrioid/genetics* ; Colorectal Neoplasms, Hereditary Nonpolyposis/pathology* ; DNA Mismatch Repair ; Endometrial Neoplasms/pathology* ; Female ; Humans ; Middle Aged ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/metabolism* ; Tumor Suppressor Protein p53/metabolism*

Lynch syndrome (LS) is an autosomal dominant hereditary disease caused by deletion of such DNA mismatch repair (MMR) genes as MLH1, MSH2, MSH6, and PMS2. The functional loss of MMR genes results in instability of the highly repetitive DNA sequence, and may eventually leads to tumor occurrence. Here we report a case of LS- related endometrial cancer in a clustered LS family identified by genetic counseling and genetic testing. For patients with a family history of LSrelated tumors, the diagnosis of LS should be considered, and immunohistochemical testing of MMR and genetic testing for LS should be performed. A definite diagnosis of LS has important clinical significance for individuals and family members, and risk screening and preventive measures can minimize the overall risk of developing LS-related cancers.
Colorectal Neoplasms, Hereditary Nonpolyposis/pathology* ; DNA Mismatch Repair ; Endometrial Neoplasms/pathology* ; Female ; Genetic Testing/methods* ; Humans

OBJECTIVE: To investigate the completeness of pedigree and of number of pedigree analysis to know the acceptable familial history in Korean women with ovarian cancer. METHODS: Interview was conducted in 50 ovarian cancer patients for obtaining familial history three times over the 6 weeks. The completeness of pedigree is estimated in terms of familial history of disease (cancer), health status (health living, disease and death), and onset age of disease and death. RESULTS: The completion of pedigree was 79.3, 85.1, and 85.6% at the 1st, 2nd, and 3rd time of interview and the time for pedigree analysis was 34.3, 10.8, and 3.1 minutes, respectively. The factors limiting pedigree analysis were as follows: out of contact with their relatives (38%), no living ancestors who know the family history (34%), dispersed family member because of the Korean War (16%), unknown cause of death (12%), reluctance to ask medical history of relatives (10%), and concealing their ovarian cancer (10%). The percentage of cancers revealed in 1st (2%) and 2nd degree (8%) relatives were increasing through surveys, especially colorectal cancer related with Lynch syndrome (4%). CONCLUSION: Analysis of pedigree at least two times is acceptable in Korean woman with ovarian cancer from the first study. The completion of pedigree is increasing, while time to take family history is decreasing during three time survey.
Adult ; Age Distribution ; Age of Onset ; Aged ; Colorectal Neoplasms, Hereditary Nonpolyposis/genetics ; Cross-Sectional Studies ; Female ; Genetic Predisposition to Disease ; Humans ; Medical History Taking/*methods ; Middle Aged ; Neoplasm Staging ; Ovarian Neoplasms/*genetics/pathology ; Pedigree ; Young Adult

BACKGROUND: During specimen processing in surgical pathology laboratories, specimen-related adverse events (SRAEs), such as mislabeling and specimen mixed-up might occur. In these situations, molecular techniques using short tandem repeat (STR) loci are required to identify the personal identity. Microsatellite instability (MSI) test is widely used for screening the hereditary non-polyposis colon cancer (Lynch syndrome) in surgical pathologies using polymorphic STR markers. We tried to evaluate the applicability of the MSI test for SRAEs. METHODS: We obtained 253 MSI test results to analyze the allele frequencies. After calibrating the estimated nucleotide lengths, we calculated the allele frequencies, a random match probability, and a likelihood ratio (LR) of three dinucleotide STR markers (D5S349, D17S250, and D2S123). RESULTS: The distribution of LR was 136.38 to 5,606,213.10. There was no case of LR<100. In addition, there were 153 cases (60.5%) of LR ranging from 100 to 10,000 and 100 cases (39.5%) of LR>10,000. Furthermore, the combined probability of identity was 9.23x10(-4) and the combined power of exclusion was 0.99908. CONCLUSIONS: Using the three STR markers that are recommended for MSI test, all the cases were positively identified in 1% range and about one-third cases showed high LR (>10,000). These results showed that MSI tests are useful to screen the personal identity in case of SRAE in pathology laboratories.
Biometric Identification ; Colonic Neoplasms ; Colorectal Neoplasms, Hereditary Nonpolyposis ; Gene Frequency ; Humans ; Mass Screening ; Microsatellite Instability ; Microsatellite Repeats ; Pathology, Surgical ; Succinimides

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma, Clear Cell ; genetics ; metabolism ; pathology ; surgery ; Adenosine Triphosphatases ; metabolism ; Age Factors ; Carcinoma, Endometrioid ; genetics ; metabolism ; pathology ; surgery ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; metabolism ; pathology ; surgery ; Cystadenocarcinoma, Serous ; genetics ; metabolism ; pathology ; surgery ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Female ; Humans ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasms, Multiple Primary ; genetics ; metabolism ; pathology ; surgery ; Nuclear Proteins ; metabolism

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominantly inherited disease associated with germ-line mutations in mismatch repair genes and microsatellite instability. This article reviews the molecular biology and clinical pathology of HNPCC.
Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; pathology ; DNA Mismatch Repair ; Humans ; Microsatellite Instability

Adenomatous Polyposis Coli ; genetics ; pathology ; Colonic Neoplasms ; classification ; genetics ; pathology ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; DNA Glycosylases ; metabolism ; Humans ; Intestinal Polyps ; pathology ; Lymphatic Metastasis ; Neoplasm Staging ; Neuroendocrine Tumors ; classification ; pathology ; Precancerous Conditions ; pathology ; Rectal Neoplasms ; classification ; genetics ; pathology ; World Health Organization

Colorectal cancer is one of the most common malignancies in the world. Many mouse models have been developed to evaluate features of colorectal cancer in humans. These can be grouped into genetically-engineered, chemically-induced, and inoculated models. However, none recapitulates all of the characteristics of human colorectal cancer. It is critical to use a specific mouse model to address a particular research question. Here, we review commonly used mouse models for human colorectal cancer.
Adenomatous Polyposis Coli ; genetics ; pathology ; Animals ; Colorectal Neoplasms ; chemically induced ; etiology ; genetics ; pathology ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; pathology ; Disease Models, Animal ; Genetic Engineering ; Humans ; Inflammation ; complications ; Mice ; Mice, Transgenic ; Neoplasm Metastasis

OBJECTIVETo analyze the clinical and pathological features of patients with hereditary nonpolyposis colorectal cancer (HNPCC).

METHODSThe data of 8 HNPCC pedigrees according with Amsterdam standard II were collected and their pedigree trees were generated.

RESULTSThe morbidity of HNPCC was 1.59%. Thirty-one patients were found in the 8 HNPCC pedigrees including 25 with colorectal cancer and 6 with extraintestinal tumors. The 8 probands consisted of 6 female and 2 male patients, among whom 4 were younger than 40 years old, 2 had lesions in the right colon, 3 in the left colon, and 3 in the rectum. The tumors were histologically identified mainly as highly to moderately differentiated adenocarcinoma; all the patients were free of lymph node or distant metastasis. Of the 8 probands, 5 had abnormal expression of MMR protein and only 1 had normal expression.

CONCLUSIONThe HNPCC probands are characterized by early onset at a young age and high differentiation of the tumor. The members of the pedigrees show a high incidence of the malignancies, and regular examination and timely treatment can be effective in preventing the tumor occurrence and reducing the mortality. Detection of MMR gene mutation can be a crucial approach to raising the diagnostic rate of HNPCC.

Adult ; Aged ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; pathology ; DNA Mismatch Repair ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree