Lynch syndrome (LS) is an autosomal-dominant inherited disorder mainly caused by a germline mutation in the DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) and is associated with increased risk for various cancers, particularly colorectal cancer and endometrial cancer (EC). Women with LS account for 2% to 6% of EC patients; it is clinically important to identify LS in such individuals for predicting and/or preventing additional LS-associated cancers. PMS2 germline mutation (PMS2-LS) is the rarest contribution to LS etiology among the 4 LS-associated MMR germline mutations, and its detection is complicated. Therefore, prudent screening for PMS2-LS is important as it leads to an efficient LS identification strategy. Immunohistochemistry is recommended as a screening method for LS in EC. Isolated loss of PMS2 (IL-PMS2) expression is caused not only by PMS2-LS but also by MLH1 germline mutation or MLH1 promoter hypermethylation (MLH-PHM). This study aimed to determine the association between MLH1-PHM and IL-PMS2 to avoid inappropriate genetic analysis. We performed MLH1 methylation analysis and MLH1/PMS2 germline mutation testing on the IL-PMS2 cases. By performing MMR-immunohistochemistry on 360 unselected ECs, we could select 8 (2.2%) cases as IL-PMS2. Heterogenous MLH1 staining and MLH1-PHM were detected in 4 of 8 (50%) IL-PMS2 tumors. Of the 5 IL-PMS2 patients who underwent genetic analysis, 1 had PMS2 germline mutation with normal MLH1 expression (without MLH1-PHM), and no MLH1 germline mutation was detected. We suggest that MLH1 promoter methylation analysis for IL-PMS2 EC should be performed to exclude sporadic cases before further PMS2 genetic testing.

Adjuvant chemotherapy may not be necessary for patients with stage IA or IB epithelial ovarian cancer, but may be beneficial for clear cell carcinoma patients with intraoperative tumor rupture.

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Endometrial cancer (EC) rates are rising in Japan. Lymph node (LN) metastasis is an important prognostic factor in EC, and its risk is increased with higher tumor grade, deep myometrial invasion, larger tumor size, and lymphovascular space invasion (LVSI). Current methodologies to assess these factors are unreliable. We previously showed the association between C-reactive protein (CRP) 1846C>T (rs1205) polymorphism and LN metastasis in esophageal, non-small cell lung, and breast cancers. The CRP gene is located on chromosome 1q21-q23, and the polymorphism in the noncoding region (1846C>T) of this gene decreases serum CRP levels. We investigated the relationship between CRP 1846C>T genetic polymorphism and LN metastasis or LVSI in 130 EC patients using polymerase chain reaction-restriction fragment length polymorphism. The CRP 1846C/T genotype was C/C in 11 patients, C/T in 58 patients and T/T in 61 patients. The patients were divided into two groups based on their CRP 1846 genotypes: "C/C" and "C/T + T/T". Nine (7%) and 18 (13%) patients, all with the polymorphism, had LN metastasis and moderate or prominent lymphatic invasion, respectively. LN metastasis and/or severe lymphatic invasion were observed in the C/T + T/T group, while patients with the C/C genotype had no LN metastases or severe lymphatic invasion. Univariate and multivariate logistic regression models revealed that the C/T + T/T patients had a significant likelihood of developing LN metastasis and/or severe lymphatic invasion. Our results suggest that CRP genetic polymorphism is a novel risk predictor of LN metastasis and/or lymphatic invasion in EC.

Lynch syndrome (LS) is an inherited disorder caused by a germline mutation in the DNA mismatch repair (MMR) genes and is associated with increased risk of various cancers, particularly colorectal cancer and endometrial cancer (EC). It is significant to identify LS in EC patients for prediction and prevention of the succeeding other associated cancers. However, useful LS screening guidelines for EC have not been established. The purpose of our study is to devise an efficient and practical screening strategy for LS in EC. We designed original criteria, named "APF criteria," with lenient terms (Age of onset < 50, or Personal or Family history of associated cancers) and applied it to unselected EC patients. We performed immunohistochemistry (IHC) and the methylation assay of MutL homolog 1 (MLH1) gene promoter using the tumors of patients who met our criteria, and thus selected "suspected LS" as the candidates for genetic analyses. Of 360 EC patients, 187 (51.9%) met the APF criteria, and the tumor specimens were available from 182 out of the 187 patients. IHC revealed that expression of at least one MMR protein was absent in cell nuclei of 54 (29.6%) tumors. Of 20 tumors lacking MLH1 protein expression, 14 cases were judged sporadic EC because of the hypermethylated MLH1 promoter. We thus selected 40 (11.1%) of 360 EC patients as "suspected LS." Our strategy that consists of clinical triage and the molecular analyses is expected to improve the screening efficiency and reduce the cost of LS identification in EC.