林奇综合征相关子宫内膜癌研究进展

林奇综合征(lynch syndrome,LS)是一种常染色体显性遗传病,既往称为遗传性非息肉病性结直肠癌(hereditary nonpolyposis colorectal cancer,HNPCC),是由DNA错配修复(mismatch repair,MMR)基因MLH1、MSH2、MSH6和PMS2的胚系突变引起。LS患者有多种癌变倾向、发病低龄化及家族易感性,可同时或异时发生结直肠癌、子宫内膜癌(endometrial cancer,EC)、卵巢癌、胃癌和乳腺癌等,女性患者中EC与之最为密切,目前我国对于LS相关EC(LS-EC)认识尚不足,并未形成完整的诊疗标准或指南。为提高对LS-EC的认识,综述LS-EC的分子机制、临床病理特征、筛查及诊断、临床治疗手段、预防等。     

“Lynch综合征相关妇科肿瘤监管的曼彻斯特国际共识”要点解读

正Lynch综合征(Lynch syndrome,LS)是一组常染色体显性遗传的癌症综合征,主要包括结直肠癌(colorectal cancer,CRC)、子宫内膜癌(endometrial cancer,EC)以及卵巢癌(ovarian cancer,OC)[1]。LS的发病根源是由于细胞DNA的错配修复(MMR)系统中的MLH1、MSH2、MSH6和PMS2的基因突变,其阻碍了细胞DNA合成过程中的错配修复[2]。早期及时诊断可以对癌症的预测及下一步治疗产生影响。目前,已证实LS患者进行CRC监管可以获得很好的生存获益[3],而国际上LS相关CRC监管的临床指南,并不完全适合妇科肿瘤。在女性中,LS的首发肿瘤多为EC,而且由于子宫内膜癌的前驱症状较明显,临床多早期发现,早     

Lynch综合征相关妇科肿瘤的临床思考

Lynch综合征(lynch syndrome,LS),又称遗传性非息肉状结直肠癌(hereditary non-polyposis colorectal cancer,HNPCC),属常染色体显性遗传性疾病,由DNA错配修复(mismatch repair,MMR)基因突变引起,其发病率约占结直肠癌的2％ ～5％[1-2].根据有无肠外肿瘤将LS分为Ⅰ型和Ⅱ型:Ⅰ型仅表现为结直肠癌;Ⅱ型除结直肠癌外,还表现为多样性肠外肿瘤,常见的有子宫内膜癌和卵巢癌.某些Ⅱ型LS患者家族中还发生其他恶性肿瘤,如胃癌、小肠癌、胰腺癌、甲状腺癌、尿道癌、脑肿瘤、皮肤癌等.近年,越来越多的证据显示,女性LS患者一生中发生子宫内膜癌(内膜癌)的风险为40％～60％,已超过结直肠癌(49％).更有意义的是,高达68％的LS患者首发恶性肿瘤为内膜癌.     

林奇综合征相关卵巢癌新进展

林奇综合征（Lynch syndrome,LS）是一种常染色体显性肿瘤综合征,是由DNA错配修复（MMR）基因中的一个胚系突变使细胞具有高微卫星不稳定表型（MSI-H）的超突变或缺乏MMR蛋白表达从而引起肿瘤的发生。突变携带者具有罹患结直肠癌、子宫内膜癌和卵巢癌等一系列恶性肿瘤的高风险。虽然LS中最常见的是结直肠癌,但约有60％的LS首发癌为妇科恶性肿瘤（如子宫内膜癌、卵巢癌等）,且其被诊断年龄较早、组织病理学大多为子宫内膜样或非浆液性类型、总体存活率良好。因此及时发现LS相关卵巢癌（LSAOC）这一亚类,对于预防LS患者其他肿瘤的发生,提高LS患者的生存率具有重要意义。目前关于LS的发病机制、组织病理学等方面不断有新的探索,现就LSAOC的早期诊断、组织病理学、筛查及降低风险方案的最新进展进行综述。     

曼彻斯特国际共识小组对Lynch综合征相关妇科癌症管理指南的解读

Lynch 综合征是一种常染色体显性遗传性癌症综合征,是由于 DNA 错配修复 (mismatch repair, MMR) 相关基因MLH1、MSH2、MSH6、PMS2的致病性突变所致,包括结直肠癌、子宫内膜癌及卵巢癌等[1-2].对Lynch综合征的诊断不仅可以为患者自身的治疗、随访及监测等提供有效的指导,而且可...     

免疫组化检测子宫内膜癌中MMR蛋白的抗体组合优化

目的:比较MLH1、MSH2和PMS2、MSH6两种抗体组合在子宫内膜癌(EC)MMR蛋白表达缺失的敏感性,优化检测EC中MMR蛋白表达缺失的抗体组合。方法:选取126例EC肿瘤组织,应用免疫组化法检测EC中MLH1、MSH2、PMS2和MSH6蛋白的表达。结果:126例子宫内膜癌中MLH1和MSH2蛋白缺失的检出率为22.22%(28/126),PMS2和MSH6蛋白缺失的漏诊率为6.35%(8/126);PMS2和MSH6蛋白缺失的检出率为29.37%(37/126),MLH1和MSH2蛋白缺失的漏诊率为5.56%(7/126)。结论:应用MLH1、MSH2和PMS2、MSH6两种抗体组合均不能完全检测到MMR蛋白的表达缺失,仍需联合应用四种抗体检测EC中MMR蛋白的表达缺失,防止某一种MMR蛋白表达缺失病例的漏诊。     

Lynch综合征与妇科肿瘤

Lynch综合征又称遗传性非息肉性结直肠癌综合征(hereditary non-polyposis colorectal cancer,HNPCC),属常染色体显性遗传性疾病,由DNA错配修复(mismatch repair,MMR)基因突变引起。Lynch综合征根据有无肠外肿瘤分为Ⅰ型（无肠外肿瘤）和Ⅱ型（有肠外肿瘤）,Ⅰ型仅表现为结直肠癌;Ⅱ型除结直肠癌外,还表现为多样性肠外肿瘤,常见有子宫内膜癌和卵巢癌,在某些Lynch综合征Ⅱ型患者的家族中还有其他恶性肿瘤的发生,如输尿管和肾盂的移行细胞癌、胃癌、小肠癌、胰腺癌、甲状腺癌、脑肿瘤、皮肤癌等。在子宫内膜癌患者中,约5％的患者与遗传因素有关,其中Lynch综合征占大多数[1];在卵巢癌患者中,5％～10％的患者与遗传有关,其中BRCA1、BRCA2基因突变引起的遗传性乳腺癌-卵巢癌综合征(HBOCS)和Lynch综合征Ⅱ型占大多数。目前,有关Lynch综合征相关性结直肠癌的发病过程和分子学特征研究较多,而Lynch综合征相关性妇科肿瘤的研究较少。本文对Lynch综合征相关性子宫内膜癌和卵巢癌的诊断、发病风险、临床病理特征、筛查及预防进行综述。     

早期子宫内膜癌保留生育功能治疗专家共识（2022年版）

<正>一、概述子宫内膜癌（endometrial cancer, EC）是女性生殖道常见恶性肿瘤,约25%的患者发生在绝经前,3%～5%的患者发病年龄<40岁,并且近年来年轻子宫内膜癌患者发病率呈上升趋势。约80%的年轻子宫内膜癌为Ⅰ型,分化良好。年轻子宫内膜癌患者的临床及病理特征为：(1)月经不规律,或不规则阴道流血,少数患者月经无异常;病史中经常合并肥胖、多囊卵巢综合征（polycystic ovarian syndrome, PCOS）及不孕不育等。(2)组织类型为子宫内膜样腺癌（endometrioid adenocarcinoma, EA）,     

MMR蛋白在Lynch综合征相关子宫内膜癌初筛中的应用

目的:通过检测错配修复(MMR)蛋白在子宫内膜癌(EC)中的表达情况,探讨MMR蛋白在Lynch综合征相关EC中筛查的可行性。方法:收集2015年6月至2018年6月于青岛市市立医院行免疫组化法检测MMR蛋白(MLH1/MSH2/MSH6/PMS2)表达的EC患者80例,分析MMR蛋白表达缺失病例的临床资料及肿瘤组织病理学特点,其中2例行全外显子测序明确基因突变位点。结果:80例EC患者中,MMR蛋白表达缺失者22例(27.5%),其中以MLH1和PMS2蛋白缺失表达为主。MMR蛋白表达缺失者年龄相对更小,以子宫下段居多(P0.05)。其中2例经全外显子基因测序验证了相应MMR基因的突变。结论:免疫组化检测MMR蛋白表达缺失可用于Lynch综合征相关EC的初筛。MMR蛋白表达缺失与患者低龄及病灶部位相关。对于经济条件允许的患者,可进一步行全外显子测序确定相关基因的突变位点。     

MSH2基因13号外显子移码突变致Lynch综合征相关子宫内膜癌一例

子宫内膜癌是女性常见的恶性肿瘤之一,绝大部分子宫内膜癌为散发型,只有2%为遗传型,遗传型子宫内膜癌也称为Lynch综合征相关性子宫内膜癌(LS-EC)。本例患者43岁,因子宫下段赘生物活检提示子宫内膜低分化腺癌,行子宫内膜癌根治性手术,因肿瘤位于子宫下段,且病理特征提示子宫内膜样腺癌,因存在多个高危因素故行Lynch综合征筛查。根据2019年Manchester国际共识,妇科肿瘤筛查Lynch综合征的流程明确,首先采用免疫组化法检测丢失的蛋白,发现潜在的突变基因,最终通过高通量测序(NGS)技术确诊为MSH2基因13号外显子E701fs移码突变导致的LS-EC。     

Occult endometrial cancer and decision making for prophylactic hysterectomy in hereditary nonpolyposis colorectal cancer patients

BACKGROUND AND OBJECTIVE: Hereditary nonpolyposis colorectal cancer (HNPCC) is the most frequent form of hereditary colorectal cancer. In addition to the high lifetime risk for colorectal cancer in mutation carriers, there is also a remarkably increased risk for endometrial cancer (EC). METHODS: In this retrospective study, clinical and molecular approach to the individual decision making as to whether or not to perform a prophylactic hysterectomy in a subset of HNPCC patients is discussed. 147 female patients meeting at least one criterion of the Bethesda guidelines were included in this analysis between 1995 and 2003. After clinical and genetic counseling, patients gave informed written consent and microsatellite analysis, immunohistochemistry and sequencing of the mismatch repair genes MLH1, MSH2 and MSH6 was performed. RESULTS: 11 of the analyzed patients had a personal history of EC and had undergone previous hysterectomy at ages 26 to 62 years. Prophylactic hysterectomy with oophorectomy was considered in postmenopausal women meeting the Amsterdam criteria and/or carrying a disease causing mismatch repair gene mutation who were operated on because of diagnosed colorectal cancer in our center for hereditary cancer. This procedure was performed in 4 patients. None of them had shown any symptoms of a gynecologic malignancy. Preoperative gynecological examination showed no evidence for EC or ovarian cancer in these patients. Postoperative histological examination showed EC stage T1b N0 M0 in 2 patients. CONCLUSIONS: Since the efficiency of gynecological surveillance is uncertain, prophylactic hysterectomy could be an option for a subset of HNPCC patients and mutation carriers.     

不同分子学筛查方法在Lynch综合征相关子宫内膜癌患者中的对比分析#br#

Objective?Compare the accuracy of immunohistochemical staining (IHC), microsatellite instability detection (MSI), and the combined detection of the two in the screening of Lynch Syndrome-related endometrial cancer (LS-EC), and analyze the advantages and disadvantages of actual clinical applications, to identify a routine and reasonable screening strategy. This study also reveals the incidence of LS-EC and the mutations of different mismatch repair (MMR) genes in the Chinese population in this region. Methods?IHC MMR protein detection and MSI detection were performed on the pathological tissues of diagnosed EC patients from the Second Hospital of Jilin University from November 2019 to November 2020, and the preoperative venous blood was subjected to next-generation sequencing (NGS) of Lynch syndrome-related mutations. Results?After NGS testing, 8 cases of LS were confirmed, with an incidence rate of 7.90%. 28 cases had lack of expression of MMR protein, 7 cases were diagnosed as LS, 1 case was missed diagnosis; 13 cases had high microsatellite instability (MSI-H), 3 cases were diagnosed as LS, 5 cases were missed; the combined detection of the two tests can screen out all LS patients. Conclusion?IHC combined with MSI screening is highly sensitive but not cost-effective. IHC alone is recommended as the first clinical screening method.     

Prospective evaluation of molecular screening for Lynch syndrome in patients with endometrial cancer ≤ 70 years

Objective

Lynch syndrome (LS) is a hereditary syndrome that predisposes to multiple malignancies including endometrial cancer (EC). We aimed to evaluate a diagnostic strategy for LS based on routine analysis of microsatellite instability (MSI) and immunohistochemical (IHC) staining for mismatch repair (MMR) proteins in tumour tissue of all newly diagnosed EC patients ≤ 70 years.

Methods

Consecutive EC patients ≤ 70 years were included prospectively in eight Dutch centres. EC specimens were analysed for MSI, IHC of four MMR proteins, MMR gene methylation status and BRAF-mutations. tumours were classified as; 1) likely to be caused by LS, 2) sporadic MSI-H, or 3) microsatellite stable (MSS).

Results

Tumour specimens of 179 patients (median age 61 years, IQR 57-66) were analysed. In our study 92% of included patients were over 50 years of age. Eleven EC patients were found likely to have LS (6%; 95% CI 3-11%), including 1 patient suspected of an MLH1, 2 of an MSH2, 6 of an MSH6 and 2 of a PMS2 gene defect. Germline mutation analyses revealed 7 MMR gene germline mutations. Ten patients likely to have LS (92%) were older than 50 years. In addition, 31 sporadic MSI-H tumours with MLH1 promoter hypermethylation (17%; 95% CI 13-24%) were identified.

Conclusions

Molecular screening for LS in patients with EC diagnosed ≤ 70 years, leads to identification of a profile likely to have LS in 6% of cases. New screening guidelines for LS are needed, including recommendations for EC patients older than 50 years of age.     

Atypical clustering of gynecologic malignancies: A family study including molecular analysis of candidate genes

OBJECTIVE: We set out to determine whether hereditary nonpolyposis colorectal cancer (HNPCC) was responsible for cancer susceptibility in a family with gynecologic malignancies in three consecutive generations. METHODS: A detailed family history study, including review of medical records, was undertaken. Tumor DNAs from affected family members were evaluated for microsatellite instability (MSI). Linkage between cancer susceptibility and the candidate DNA mismatch repair genes MLH1, MSH2, MSH3, and MSH6 (GTBP) was investigated. MLH1 and MSH2 protein expression was evaluated by immunohistochemistry and MSH2 was investigated for mutation. RESULTS: Four gynecologic malignancies in the core family were confirmed. MSI was seen in six of seven cancers studied. The only MSI-negative tumor was an ovarian cancer from the proband's maternal grandmother, which arose at the age of 92. Haplotype analysis using chromosome 2p markers implicated the MSH2 gene in this family's cancer susceptibility. MSH2 protein expression was absent in an MSI-positive colon cancer from an affected family member. CONCLUSIONS: The inability to exclude linkage of MSH2 with the disease susceptibility, the presence of the MSI phenotype in cancers from family members sharing the same region of chromosome 2p, and the lack of immunodetectable MSH2 point to MSH2-associated HNPCC as a cause for this family's cancer susceptibility. Continued efforts to increase awareness of the heritability of endometrial cancer should improve our understanding of the disease, with resultant improved surveillance strategies, recommendations for surgical and chemoprophylaxis, and identification of patients at risk for malignancy as a result of HNPCC.     

Universal Testing to Identify Lynch Syndrome Among Women With Newly Diagnosed Endometrial Carcinoma

BackgroundLynch syndrome (LS) is an autosomal dominant cancer syndrome caused by a germline mutation in the mismatch repair (MMR) genes. Protocols based on immunohistochemical expression of MMR proteins in cancer are used to identify patients with LS.MethodsThe universal LS screening protocol of the Tom Baker Cancer Centre (Calgary, AB) of all patients diagnosed between April 1, 2013 and April 1, 2015 with endometrioid carcinoma of the endometrium was audited through a retrospective chart review. LS status and frequency of protocol compliance at each of the key steps were calculated (Canadian Task Force Classification II-2).ResultsThe cohort consisted of 375 patients. MMR immunohistochemical testing was requested for 321 (85.6%). Expression of at least one protein was lost in 86 (26.8%). Twenty-one (6.5%) patients were eligible for genetic counselling because PMS2, MSH2, or MSH6 protein expression was lost in 19, and two patients had a family history of LS. Eleven (91.7%) of 12 (57.1%) who attended had germline testing, and six (54.5%) showed a mutation diagnostic of LS. LS status among the cohort of 375 patients was positive in six (1.6%), negative in 294 (78.4%), and unknown in 75 (20%) because of protocol non-compliance. LS was confirmed in six (2%) of the 321 women who completed the protocol.ConclusionThis 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.     

Ovarian cancer at young age: the contribution of mismatch-repair defects in a population-based series of epithelial ovarian cancer before age 40

At least one of ten patients with ovarian cancer is estimated to develop their tumor because of heredity with the breast and ovarian cancer syndrome due to mutations in the BRCA1 and BRCA2 genes and hereditary nonpolyposis colorectal cancer (HNPCC) being the major genetic causes. Cancer at young age is a hallmark of heredity, and ovarian cancers associated with HNPCC have been demonstrated to develop at a particularly early age. We used the Swedish Cancer Registry to identify a population-based series of 98 invasive epithelial ovarian cancers that developed before 40 years. Mucinous and endometrioid cancers were overrepresented and were diagnosed in 27% and 16% of the tumors, respectively. Immunostaining using antibodies against MLH1, PMS2, MSH2, and MSH6 was used to assess the mismatch-repair status and revealed loss of expression of MLH1/PMS2 in two cases, loss of MSH2/MSH6 in one case, and loss of MSH6 only in three tumors. A microsatellite instability-high phenotype was verified in five of six tumors. Based on the identified mutations and family history of cancer, several of these individuals are likely to be affected by HNPCC. We conclude that although the causes of the vast majority of epithelial ovarian cancer at young age are unknown, HNPCC should be considered because of the high risk of metachronous colorectal cancer in the individual and the possibility of preventing additional cancers in the family through control programs.     

The contribution of the hereditary nonpolyposis colorectal cancer syndrome to the development of ovarian cancer

OBJECTIVE: Ovarian cancer has one of the highest fractions of hereditary cases. The hereditary breast and ovarian cancer syndrome, primarily due to mutations in BRCA1 and BRCA2, is the main cause of heredity, but also the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome confers an increased risk of ovarian cancer. In order to clarify the contribution of HNPCC to the development of ovarian cancer, we collected data on family history of cancer and characterized MMR function in a consecutive series of 128 tumors unselected for age at diagnosis and previously characterized for BRCA gene mutations. METHODS: Expression of the MMR proteins MLH1, PMS2, MSH2, and MSH6 was analyzed by immunohistochemistry using tissue microarray sections. Tumors with reduced staining or loss of staining were also analyzed for microsatellite instability (MSI). RESULTS: Loss of MMR protein expression was identified in 3 ovarian cancers, all of which had a MSI-high phenotype. DNA sequence analysis revealed disease-causing germline mutations (deletions of exons 4-6 in MLH1 and a 1-nucleotide deletion in exon 5 of MSH6) in two patients diagnosed at ages 40 and 49 years, both of whom had family histories suggestive of HNPCC. The genetic defect in the third case, which was a 47-year old woman without knowledge about her family history with loss of MLH1/PMS2 expression in the tumor tissue, remains elusive. A family history suggestive of HNPCC was identified in an additional case, but this tumor showed normal, retained MMR protein expression and a microsatellite stable phenotype. CONCLUSIONS: About 2% of ovarian cancer is caused by germline mutations in the MMR-genes, a minor proportion as compared to the contribution of the BRCA-genes (11% in the present series). However, identification of HNPCC patients is important since it allows inclusion of high-risk individuals into control programs aimed at preventing the more frequent colorectal and endometrial cancers. Tumors within the HNPCC-spectrum should therefore be included when recording a family history of cancer among patients diagnosed with ovarian cancer.     

Hereditary risk of women's cancers

The characterization of specific genes responsible for the hereditary risk of common cancers has enabled the development of clinical tests designed to identify at-risk individuals and to significantly improve the clinical outcome of such individuals. Two of the most important syndromes associated with a hereditary risk of cancer in women are hereditary breast and ovarian cancer, resulting from the BRCA1 and BRCA2 genes, and hereditary non-polyposis colorectal cancer, caused primarily by the MLH1 and MSH2 genes. As testing for the hereditary risk of breast, ovarian, endometrial and colorectal cancer enters the clinical mainstream, physicians responsible for the health care of women are increasingly required to assess and provide guidance to healthy patients with a strong family history, cancer survivors who may be at risk of a second cancer and women who discover that a family member carries a specific mutation identified through genetic testing. Obstetricians and gynaecologists must therefore become familiar with the principles of assessing the family history for specific hereditary cancer syndromes, with the appropriate use of tests to confirm such syndromes and with the management options for women who have inherited a greatly increased risk of cancer.     

Mismatch repair protein deficiency in endometriosis: Precursor of endometriosis-associated ovarian cancer in women with lynch syndrome

ObjectiveWe aimed to elucidate the pathogenesis of ovarian cancer through the loss of mismatch repair (MMR) proteins in women with Lynch syndrome (LS) in this report.Case reportTwo women with LS underwent surgery for synchronous endometrial cancer and ovarian cancer. In both cases, immunohistochemical examination showed concomitant MMR protein deficiency in endometrial cancer, ovarian cancer, and contiguous ovarian endometriosis. In Case 1, the macroscopically normal ovary included multiple endometrioses with MSH2 and MSH6 expression, and FIGO grade 1 endometrioid carcinoma and contiguous endometriosis without MSH2 and MSH6 expression. In Case 2, all endometriotic cells contiguous with carcinoma in the lumen of the ovarian cyst showed loss of the expression of MSH2 and MSH6.ConclusionOvarian endometriosis with MMR protein deficiency may progress to endometriosis-associated ovarian cancer in women with LS. Diagnosing endometriosis in women with LS during surveillance is important.