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: Lynch syndrome is a cancer predisposition syndrome caused by germline mutation of DNA mismatch repair (MMR) genes. Lynch syndrome only causes about 0.4% of cases of ovarian cancer, which suggests that universal screening may not be cost-efficient. However, the frequency of Lynch syndrome in ovarian cancer is unclear in the Asian population. The goal of the study was to investigate a screening strategy using family history. METHODS: The subjects were 129 patients with ovarian cancer. Clinical and family history were collected using a self-administered questionnaire, and Society of Gynecologic Oncology (SGO) criteria 2007 and PREMM5 were used for risk assessment. Microsatellite instability, immunohistochemistry, and methylation of MMR genes were analyzed. RESULTS: Of the 129 cases, 25 (19.4%) met the SGO criteria, and 4 of these 25 had MSI-high and MMR deficiency. Two cases had loss of MSH2 and MSH6, indicating MSH2 mutation, and the other two had loss of MLH1 and PMS2, including one without MLH1 methylation indicating MLH1 mutation. These results show that screening using family history can detect Lynch syndrome in 12.0% (3/25) of ovarian cancer cases. The 3 cases were positive for PREMM5, but negative for Amsterdam II criteria and revised Bethesda guidelines. Genetic testing in one case with MSH2 and MSH6 deficiency confirmed the diagnosis of Lynch syndrome with MSH2 mutation. CONCLUSION: This is the first study of screening for Lynch syndrome in ovarian cancer using clinical and family history in an Asian population. This approach may be effective for diagnosis in these patients.
Asian Continental Ancestry Group ; Colorectal Neoplasms, Hereditary Nonpolyposis* ; Diagnosis ; DNA Mismatch Repair ; Genetic Testing ; Germ-Line Mutation ; Humans ; Immunohistochemistry ; Mass Screening* ; Medical History Taking ; Methylation ; Microsatellite Instability ; Ovarian Neoplasms* ; Risk Assessment*

OBJECTIVE: To evaluate the importance of Lynch syndrome associated risk screening in the patients aged less than 50 years affected from endometrial cancer. METHODS: From 2007 to 2014, 41 patients affected from endometrial cancer and aged less than 50 years underwent surgery at the Complex Operative Unit of Gynecology and Obstetrics, Cannizzaro Hospital of Catania, Italy. They were selected to undergo mismatch repair gene mutation analysis using immunohistochemistry (IHC; four markers: MLH1, MSH2, MSH6, PMS2) and microsatellite instability (MSI) test. For samples that resulted negative to IHC (abnormal finding), MSI test was performed to further study the suspected mutation. Samples were classified as MSI-high (MSI-H) if more than one marker was identified as unstable; MSI-low (MSI-L) if only one marker was identified as unstable; or MSI-stable (MSI-S) if no marker was identified as unstable. Samples were subdivided into two groups: MSI-H/L and MSI-S. Statistical analysis was performed to assess differences regarding survival, tumor staging, grading, and invasion of lymphovascular space between these two groups. RESULTS: IHC analysis showed that in 46% (19/41) of samples there was negative outcome. Forty-two percent (8/19) of these negative samples were unstable (either low or high). Of eight patients showing MSI, 75% were MSI-L, while 25% were MSI-H. Differences in survival, stage, grade, lymphovascular space invasion and Amsterdam criteria adherence were not statistically significant due to the small size of the cohort. CONCLUSION: IHC and MSI test results of our cohort lead us to assess the relevance of performing Lynch syndrome genetic screening in endometrial cancer patients aged less than 50 years at the time of diagnosis.
Cohort Studies ; Colorectal Neoplasms, Hereditary Nonpolyposis ; Diagnosis ; DNA Mismatch Repair ; Endometrial Neoplasms* ; Female ; Genetic Testing* ; Gynecology ; Humans ; Immunohistochemistry ; Italy ; Mass Screening ; Microsatellite Instability ; Neoplasm Staging ; Obstetrics

Hereditary nonpolyposis colorectal cancer (HNPCC) is the most common hereditary colorectal cancer syndrome and accounts for about 5% of colorectal cancer. It is inherited as autosomal dominant type and is caused by germline mutations in mismatch repair genes such as MLH1, MSH2, MSH6, and PMS2. Patients with HNPCC are characterized by a high level of microsatellite instability. They commonly develop colorectal cancer at young age and increase risk of extra-colic malignancies, especially endometrial cancer. They also show better oncologic outcomes compared to sporadic colorectal cancer. Several tools are used in diagnosis of HNPCC, including history taking, microsatellite instability test, immunohistochemistry for mismatch repair protein, and gene test. Affected patients and their families should get genetic counseling and regular surveillance for cancers, which can improve their survival rate.
Colorectal Neoplasms ; Colorectal Neoplasms, Hereditary Nonpolyposis* ; Diagnosis ; DNA Mismatch Repair ; Endometrial Neoplasms ; Female ; Genetic Counseling ; Genetic Testing ; Germ-Line Mutation ; Humans ; Immunohistochemistry ; Microsatellite Instability ; Survival Rate

PURPOSE: The Korean Hereditary Tumor Registry, the first and one of the largest registries of hereditary tumors in Korea, has registered about 500 families with hereditary cancer syndromes. This study evaluates the temporal changes in clinicopathologic features and surgical patterns of Lynch syndrome (LS) patients. MATERIALS AND METHODS: Data on 182 unrelated LS patients were collected retrospectively. The patients were divided into the period 1 group (registered in 1990-2004) and 2 (registered in 2005-2014). The clinical characteristics of the two groups were compared to identify changes over time. RESULTS: The period 1 group included 76 patients; the period 2 group, 106 patients. The mean ages at diagnosis were 45.1 years (range, 13 to 85 years) for group 1 and 49.7 years (range, 20 to 84 years) for group 2 (p=0.015). The TNM stage at diagnosis did not differ significantly-period 1 group: stage 0-I (n=18, 23.7%), II (n=37, 48.7%), III (n=19, 25.0%), and IV (n=2, 2.6%); period 2 group: stage 0-I (n=30, 28.3%), II (n=35, 33.0%), III (n=37, 34.9%), and IV (n=4, 3.8%). Extended resection was more frequently performed (55/76, 72.4%) in the period 1 group than period 2 (49/106, 46.2%) (p=0.001). CONCLUSION: Colorectal cancer in patients with LS registered at the Korean Hereditary Tumor Registry is still diagnosed at an advanced stage, more than two decades after registry's establishment. Segmental resection was more frequently performed in the past decade. A prompt nationwide effort to raise public awareness of hereditary colorectal cancer and to support hereditary cancer registries is required in Korea.
Colorectal Neoplasms ; Colorectal Neoplasms, Hereditary Nonpolyposis* ; Diagnosis ; Humans ; Korea ; Neoplastic Syndromes, Hereditary ; Registries ; Retrospective Studies

To improve survival in women with endometrial cancer, we need to look at the "big picture" beyond initial treatment. Although the majority of women will be diagnosed with early stage disease and are cured with surgery alone, there is a subgroup of women with advanced and high-risk early stage disease whose life expectancy may be prolonged with the addition of chemotherapy. Immunohistochemistry will help to identify those women with Lynch syndrome who will benefit from more frequent colorectal cancer surveillance and genetic counseling. If they happen to be diagnosed with colorectal cancer, this information has an important therapeutic implication. And finally, because the majority of women will survive their diagnosis of endometrial cancer, they remain at risk for breast and colorectal cancer, so these women should be counselled about screening for these cancers. These three interventions will contribute to improving the overall survival of women with endometrial cancer.
Antineoplastic Agents/therapeutic use ; Breast Neoplasms/diagnosis/mortality ; Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis/mortality ; Early Detection of Cancer ; Endometrial Neoplasms/diagnosis/drug therapy/*mortality ; Female ; Humans ; Life Expectancy ; Risk Factors

OBJECTIVETo evaluate the application of mismatch repair (MMR) genes proteins expression to screen for Lynch syndrome in colorectal cancer patients.

METHODSOne hundred consecutive colorectal cancers cases collected from 2012 to 2013 were tested immunohistochemically for the protein expression of MLH1, MSH2, MSH6 and PMS2, and also by the ARMS method for the mutation status of BRAF genes in those cases lacking protein expression for MLH1.

RESULTSThe result of MMR immunocytochemistry showed that nine of 100 cases lacked MMR protein expression, including three cases each that were MLH1-/PMS2- and MSH2-/MSH6- respectively, two cases were MLH6- and one case was PMS2-; overall, the majority of these cases lacked protein expression of MLH1 and MSH2. The BRAF genes mutation test showed one case of mutation, indicating that the patient might have MLH1 gene methylation as a result of the mutation of BRAF genes, and that was a sporadic case. The age of onset for patients lacking MMR protein expression was lower than patients with sporadic colorectal cancer (P = 0.011). Colorectal cancers associated with the lack of MMR protein expression mostly occurred in the right colon (P = 0.001), and histomorphologically were often accompanied by mucinous adenocarcinoma (P = 0.010) and tumor lymphocytic infiltration.

CONCLUSIONImmunohistochemical staining for MMR proteins in patients with colorectal cancer, accompanied by testing for BRAF genes mutation, may be an effective approach to screen for Lynch syndrome.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; DNA Mismatch Repair ; Humans ; Immunohistochemistry ; MutL Protein Homolog 1 ; Mutation ; Nuclear Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins B-raf ; genetics ; metabolism

We have recently experienced an endometrial cancer 12 years after the diagnosis of colon cancer with Lynch syndrome. A 49-year-old Korean woman had a family history of colon cancer. Her mother had colon cancer at 56-year-old, and her brother had colon cancer at 48 years old. The patient received surgery for endometrial cancer at the same hospital 12 years after being treated for colon cancer. Immunohistochemistry showed that her endometrial tissue stained negative for MSH2. A microsatellite instability test was performed and showed the presence of instability high microsatellite instability. An hMLH2 gene mutation was detected at codon 629 codon of exon 12, in which a glutamine was replaced with an arginine (1886A>G [p.Gln629Arg]). To our knowledge, this is the first case of metachronous cancer in a Lynch syndrome family in Korea with a gap of more than ten years between cancer diagnoses.
Arginine ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms, Hereditary Nonpolyposis* ; Diagnosis ; Endometrial Neoplasms* ; Female ; Glutamine ; Humans ; Immunohistochemistry ; Korea ; Microsatellite Instability ; Middle Aged ; Mothers ; Siblings

Adenomatous Polyposis Coli ; diagnosis ; drug therapy ; genetics ; surgery ; Antineoplastic Agents ; therapeutic use ; Colectomy ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; drug therapy ; genetics ; surgery ; DNA Mismatch Repair ; Humans ; Ileostomy ; Peutz-Jeghers Syndrome ; diagnosis ; drug therapy ; genetics ; surgery

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