Mismatch Repair Protein Expression in Endometrioid Intraepithelial Neoplasia/Atypical Hyperplasia: Should We Screen for Lynch Syndrome in Precancerous Lesions?

Screening for Lynch syndrome (LS) is routinely performed in patients with endometrial carcinoma. Currently, no screening recommendations exist for LS in precancerous lesions. The study goal was to determine the incidence of abnormal protein expression in endometrioid intraepithelial neoplasia/atypical hyperplasia (EIN/AH). We analyzed mismatch repair (MMR) protein expression by immunohistochemistry in EIN/AH concurrent with MMR-deficient endometrial carcinomas, and in endometrial biopsy/curettage specimens with EIN/AH from an unselected group of patients. Of 63 patients with MMR-deficient endometrial carcinoma, 34 demonstrated loss of MLH1/PMS2 expression; 1 showed loss of PMS2 alone; 12 showed loss of MSH2/MSH6, and 15 had loss of MSH6 alone. Genetic testing identified deleterious mutations in 14 cases (LS). 15 tumors demonstrated MLH1 promoter hypermethylation. Abnormal MMR expression in EIN/AH and adjacent carcinoma was concordant in 100% of LS cases and 71% of MLH1 promoter hypermethylation cases. Of 118 patients from the unselected group with EIN/AH, 4 (3%) cases demonstrated absent expression of one or more MMR proteins. Of these, 2 patients were later confirmed to have deleterious mutations in subsequent specimens with endometrial carcinoma. The prevalence of abnormal MMR expression in EIN/AH adjacent to carcinoma and in the unselected group of patients with EIN/AH is similar to the reported prevalence of LS in endometrial carcinoma. Identifying patients at high risk f...
Source: International Journal of Gynecological Pathology - Category: Pathology Tags: Pathology of the Corpus: Original Articles Source Type: research

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CONCLUSION: This is the first audit of a Canadian-based universal LS screening protocol of patients with endometrial cancer. The success of the protocol is endorsed by the 80% compliance and by the 2% prevalence of LS, which is within the published range. PMID: 31679916 [PubMed - as supplied by publisher]
Source: Journal of Obstetrics and Gynaecology Canada : JOGC - Category: OBGYN Tags: J Obstet Gynaecol Can Source Type: research
Lynch Syndrome (LS) entails a defective DNA mismatch repair system, which is the post-replicative proofreading and editing system, ensuring our genome's integrity. LS predisposes to several cancers, most commonly colorectal and endometrial cancers. LS occurs in approximately 1 in 250 –1,000 people.LS is associated with urological malignancies with upper tract urothelial carcinoma the most common, although still clinically underestimated. Other urologic malignancies possibly associated with LS include bladder, prostate, testis, and renal cell carcinoma.
Source: Urology - Category: Urology & Nephrology Authors: Source Type: research
ConclusionsOur study suggests that it is important to recognize the presence of atypical endometrial cells in Pap tests in young patients, given its association with the finding of premalignant and malignant pathology in the subsequent endometrial biopsies.
Source: Journal of the American Society of Cytopathology - Category: Cytology Source Type: research
This review is an appraisal of the current state of knowledge of 2 enigmatic histotypes of ovarian carcinoma: endometrioid and clear cell carcinoma. Both show an association endometriosis and the hereditary nonpolyposis colorectal cancer (Lynch) syndrome, and both typically present at an early stage. Pathologic and immunohistochemical features that distinguish these tumors from high-grade serous carcinomas, each other, and other potential mimics are discussed, as are staging, grading, and molecular pathogenesis.
Source: Surgical Pathology Clinics - Category: Pathology Authors: Source Type: research
Immunohistochemistry (IHC) for mismatch repair (MMR) proteins is an established test to identify Lynch syndrome (LS) in patients with colorectal cancer and is being increasingly used to identify LS in women with endometrial and/or nonserous ovarian cancer (OC). We assessed interobserver agreement in the interpretation of MMR-IHC on endometrial and ovarian carcinomas. The study consisted of 73 consecutive endometrial cancers (n=48) and nonserous, nonmucinous epithelial OCs (n=25). Six pathologists from 2 cancer centers, one with and the other without, previous experience in interpreting MMR-IHC, evaluated MLH1, MSH2, MSH6, ...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research
Patients with Lynch syndrome have up to a 24% risk of developing ovarian carcinoma, but universal mismatch repair (MMR) protein testing of ovarian carcinomas is not standard practice in most institutions. We reviewed 104 unselected ovarian endometrioid carcinomas (OEC) for various clinicopathologic features to determine if any are predictive of MMR loss. Immunohistochemistry for all 4 MMR proteins was performed followed by MLH1 promoter methylation analysis when indicated. Overall, patients had a mean age of 55 years and tumors averaged 12 cm. Most (72%) patients had stage I tumors, 63% were grade 1, and 30% had a s...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research
Women developing endometrial cancer after tamoxifen treatment for breast cancer are more likely to develop tumours with poorer prognostic features and exhibit poorer survival after adjustment for these prognostic features. Results indicate the importance of longer ‐term monitoring of women treated with tamoxifen for cancer symptoms. Report of prior cancer is a significant indicator of MMR pathogenic variant status, but molecular analysis of endometrial tumors at diagnosis is warranted to detect all patients with Lynch Syndrome. AbstractWe hypothesized that endometrial carcinoma (EC) patients with a prior cancer diagnosis...
Source: Cancer Medicine - Category: Cancer & Oncology Authors: Tags: ORIGINAL RESEARCH Source Type: research
CONCLUSION: Advanced endometrial cancer can rarely (~7%) show somatic loss of MMR protein expression in recurrent or metastatic sites compared to matched paired primary tumor. MMR testing of recurrent or metastasis should be considered for guiding immunotherapy if primary uterine tumor exhibits abnormal subclonal MMR loss. PMID: 30340772 [PubMed - as supplied by publisher]
Source: Gynecologic Oncology - Category: Cancer & Oncology Authors: Tags: Gynecol Oncol Source Type: research
Lynch syndrome (LS) is defined by germline mutations in DNA mismatch repair (MMR) genes, and affected patients are at high risk for multiple cancers. Reflexive testing for MMR protein loss by immunohistochemistry (IHC) is currently only recommended for colorectal and endometrial cancers, although upper tract urothelial carcinoma (UTUC) is the third-most common malignancy in patients with LS. To study the suitability of universal MMR IHC screening for UTUC, we investigated MMR expression and microsatellite status in UTUC in comparison to bladder UC (BUC), and evaluated the clinicopathologic features of UTUC. We found that 9...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research
Genetic factors play an important role in shaping the biologic characteristics of malignant tumors, especially in young patients. We aimed to determine the clinicopathologic features of endometrial cancer (EC) in patients younger than 50 years with a family history of cancer. Overall, 229 patients with EC, including 40 with a positive family history of cancer (PFH) and 189 with a negative family history of cancer (NFH), were enrolled in this case–control study. The family history of cancer in a 2-generation pedigree was recorded for the PFH group. Clinicopathologic features such as menarche age, body mass index, per...
Source: Medicine - Category: Internal Medicine Tags: Research Article: Observational Study Source Type: research
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