中国人遗传性大肠癌筛检标准的实施方案

遗传性大肠癌家系是研究我国大肠癌病因、遗传特征和分子改变的重要资源。随着我国计划生育国策的落实，我国家庭规模日趋小型化，收集和保存这些家系资源显得越发重要。为了抢救、保存我国宝贵的遗传性大肠癌家系，中国抗癌协会大肠癌专业委员会于2003年4月13日在杭州组织召开了成立遗传性大肠癌学组(兼全国遗传性大肠癌协作中心)的筹备会议，在工作交流的基础上，讨论制定了中国人遗传性大肠癌的筛检标准，统一规范了遗传性大肠癌家系的收集、保存和研究工作。     

遗传性非息肉病性大肠癌

目的：探讨总结遗传性卢肉病性大肠癌（ＨＮＰＣＣ）的特征,提高早期诊断和治疗水平。方法：复习文献并本结合本组四个家族的临床资料进行总结分析。结果：ＨＮＰＣＣ发病年龄轻,平均发病年龄４４岁,约６５％的患者病变发生在曲近侧结肠;约２５％的患者有多原发大肠癌;２０～７０％的患者可检测到错配修复基因（ＭＭＲ）的突变;病理分化差但有较好的预后。结论：ＨＮＰＣＣ有明显的特征,利用这些特征有助于早期诊断和制定合理     

遗传性非息肉病性大肠癌和普通遗传性大肠癌临床表型分析

目的:探讨遗传性非息肉病性大肠癌(HNPCC)与普通遗传性大肠癌临床表型的异同,为临床辨认HNPCC家系提供依据。方法:选择符合阿姆斯特丹标准Ⅱ或日本标准的22个HNPCC家系(A组)和普通遗传性大肠癌20个家系(B组)为研究对象进行随访分析。结果:1)A、B两组男女发病的比例分别为1.4:1(41/30)和1.5:1(38/26),无显著性差异(P>0.05)。2)A、B两组确诊的中位年龄分别为48岁(32～70岁)和61岁(30～83岁),50岁以前发病比例分别为59.2%和26.6%,A组较B组发病年龄明显提前,差异显著(P<0.01)。3)A、B两组右半结肠癌发病比例分别为56.9%(29/51)和29.2%(7/24),差异显著(P<0.05)。4)A组多发癌7例,B组未见多发癌。5)A组第一、二、三代的平均发病年龄分别为64岁、56岁、48岁,逐渐年轻化,B组无此现象。结论:HNPCC与普通遗传性大肠癌临床表型不尽相同,提示两者各自有其独特的遗传学特征。     

遗传性非息肉病性大肠癌的诊治进展

遗传性非息肉病性结直肠癌（HNPCC）是一种常染色体显性遗传病，错配修复基因的种系突变是发病基础，在散发性大肠癌中遴选HNPCC家族，并对HNPCC患者对其家属进行基因检测可以发现HNPCC相关肿瘤的高危人群，使家族中发病率低的成员免受长期医疗随访之苦，而且对HNPCC相关肿瘤患者进行预防性手术有较大的临床意义。     

遗传性大肠癌患者身心社会功能分析和生活质量评价

目的　探讨遗传性非息肉病性大肠癌（ＨＮＰＣＣ）患者的身心社会功能和生活质量情况及影响因素。方法 选择２００６年６月至２００９年１月上海新华医院确诊的ＨＮＰＣＣ患者为调查对象。采用单一样本问卷调查,内容包括：（１）一般人口学特征;（２）疾病及治疗情况;（３）生活质量情况：参照癌症患者生活质量测定量表（ＥＯＲＴＣＱＬＱ Ｃ３０）设计,采用多元线性回归模型分析。结果　发放问卷４７份,收回４７份。分析结果：（１）基本属性与生活质量：年龄与整体健康生活质量成负相关（ｒ＝－０.２４,Ｐ＝０.００６）,与生活品质的身体功能成负相关（ｒ＝－０.２７,Ｐ＝０.００７）;教育程度与生活质量成正相关（ｒ＝０.２１,Ｐ＝０.００３）;收入与生活质量的情绪功能和认知功能成正相关（ｒ＝０.２１,Ｐ＝０.００２;ｒ＝０.２３,Ｐ＝０.００８）;身体功能状态与整体健康生活质量成正相关（ｒ＝０.３３,Ｐ＜０.００１）。（２）生活质量多元回归分析：忧郁和年龄可解释总变异数的２９.８％;忧郁程度对生活质量有较高的解释力,解释总变异数为２４.４％,年龄的解释总变异数为５.４％。结论　ＨＮＰＣＣ患者在整个治疗康复过程中,身心社会功能和整体生活质量均有不同程度的降低,其中心理健康状态、年龄、经济状况等因素对整体生活质量的影响较大。     

遗传性非息肉病性大肠癌(10个家族27例报告)

分析遗传性非息肉病性大肠癌(HNPCC)的临床特点。方法:对10个家族27例HNPCC患者(A组)进行回顾性分析,并设30例一般大肠癌为对照组(B组)进行比较。结果:<50岁患者A组占59.3%(16/27),B组占23.3%(7/30),P<0.05。脾曲以上癌灶A组为40.0%(12/30),B组为16.1%(5/31),P<0.05。大肠多原发癌A组占10.0%(3/30),B组占3.2%(1/31)。大肠外肿瘤A组6例,B组2例。结论:HNPCC具有典型的临床特征,这些特征可以对HNPCC患者进行早期诊断及治疗,以得到较好的预后。     

遗传性非息肉病性大肠癌家系及可疑家系的临床诊断分析

目的 提高对遗传性非息肉病性大肠癌（HNPCC）临床诊断的认识。方法：对有2例以上大肠癌，或1例大肠癌并1例以上HNPCC相关肿瘤以及发病年龄小于40岁患者的家系进行家系调查和诊断分析。结果：70个家系中有8个家系符合HNPCC诊断标准，8个家系共有24例大肠癌病人，平均年龄44岁。共有大肠癌灶35个，20个分布于脾曲近端的结肠。6例为多原发大肠癌。62个家系符合可疑；HNPCC诊断标准，其中2个家系符合可疑HNPCC诊断标准Ⅰ，60个家系符合可疑HNPCC诊断标准Ⅱ。62个家系共有65例大肠癌病人，平均年龄30．5岁。共有大肠癌灶68个，49个癌灶分布于脾曲近端的结肠或直肠。2例为多原发大肠癌。结论 熟悉HNPCC诊断标准和可疑HNPCC诊断标准对临床诊断至关重要。有必要对可疑HNPCC诊断标准Ⅱ进行修改。     

大肠癌早期诊断的研究进展

正确采集粪便标本及其对FOBT方法的改进，并且与其它检查方法相结合可提高大肠癌的早期诊断率。大肠癌相关基因产物及癌肿标记物的检测已显示出可喜前景，有望成为大肠癌早期诊断的重要标记物。端粒酶活性检测对大肠癌的早期诊断已引起众多学者的关注。用激光诱光荧光测试、内腔声像法等检查方式试图提高对大肠癌的早期诊断亦初露端倪。随着蛋白芯片的出现和研究的深入，将为大肠癌的早期诊断提供特殊、便捷的方法。     

遗传性非息肉病性大肠癌11个家系32例的临床特点与诊治

目的：分析遗传性非息肉病性大肠癌的临床特点及诊治经验。方法：分析11个家系32例遗传性非息肉病性大肠癌的诊断、治疗、随访结果，分别记录肿瘤发病部位、病理结果等一般情况。结果：11个家系中共有恶性肿瘤43例61个肿瘤，其中大肠癌32例39个肿瘤。32例中至今共发生异时多原发恶性肿瘤12例，占37．5％，其中异时多原发大肠癌5例，占15．6％。通过先证者对其本人及一级亲属进行随诊检查共发现各类恶性肿瘤28个，其中20个(67．7％)为无明显临床症状者。结论：本病是一种常染色体显性遗传病，本病具有发病年龄早，好发于近侧结肠，易患异时或同时多原发癌及大肠外恶性肿瘤。在诊治中要作详细病史调查，除对先证者进行治疗和随访外．对其亲属的宣教和随访等工作亦十分重要。     

遗传性非息肉病性大肠癌两种手术方式疗效分析

目的:探讨遗传性非息肉病性大肠癌理想的手术方式.方法:回顾性分析1990年8月～2002年8月我院普外科收治的31例遗传性非息肉病性大肠癌的临床资料,17例接受大肠癌次全切术,14例接受大肠癌常规手术.比较手术前、后患者体重、血浆营养参数(血红蛋白、血清白蛋白)以及术后排便次数、术后复发率在两种手术方式组间的差异.结果:患者的体重变化、血红蛋白、血浆蛋白的变化及术后每天排便次数在两种术式组中无明显差异(P＞0.05);次全大肠切除术组复发率比常规手术方式组低,二者相比具有统计学差异(P＜0.05).结论:次全结肠切除术较大肠癌常规手术更适合于遗传性非息肉病性大肠癌的治疗.     

Hereditary colorectal cancer syndromes: molecular genetics, genetic counseling, diagnosis and management

Hereditary forms of colorectal cancer, as is the case with virtually all forms of hereditary cancer, show extensive phenotypic and genotypic heterogeneity, a phenomenon discussed throughout this special issue of Familial Cancer. Clearly, the family physician, oncology specialist, genetic counselor, and cancer geneticist must know fully the complexity of hereditary cancer syndromes, their differential diagnosis, in order to establish a diagnosis, direct highly-targeted surveillance and management, and then be able to communicate effectively with the molecular geneticist so that an at-risk patient’s DNA can be tested in accord with the syndrome of concern. Thus, a family with features of the Lynch syndrome will merit microsatellite instability testing, consideration for immunohistochemistry evaluation, and mismatch repair gene testing, while, in contrast, a patient with FAP will require APC testing. However, other germline mutations, yet to be identified, may be important should testing for these mutations prove to be absent and, therein, unrewarding to the patient. Nevertheless, our position is that if the patient’s family history is consistent with one of these syndromes, but a mutation is not found in the family, we still recommend the same surveillance and management strategies for patients from families with an established cancer-causing germline mutation. Our purpose in this paper is to provide a concise coverage of the major hereditary colorectal cancer syndromes, to discuss genetic counseling, molecular genetic evaluation, highly targeted surveillance and management, so that cancer control can be maximized for these high hereditary cancer risk patients.     

Strategies for clinical implementation of screening for hereditary cancer syndromes

Hereditary cancer syndromes generally account for 5%–10% of malignancies. While these syndromes are rare, affected patients carry significantly elevated risks of developing cancer, as do their at-risk relatives. Identification of these patients is critical to ensure timely and appropriate genetic testing relevant to cancer patients and their relatives. Several guidelines and tools are available to assist clinicians. Patients suspected to have hereditary cancer syndromes should be offered genetic testing in the setting of genetic counseling by a qualified genetics professional. Germline testing ranges from testing for a known specific familial mutation to testing of a broad differential diagnosis using a pan-cancer multi-gene panel. Taking a family history, referring specific types of tumors with higher likelihood of heredity, implementing universal screening protocols such as microsatellite instability/immunohistochemistry (MSI/IHC) for specific tumors, and referring patients with somatic tumor testing that have potentially germline consequences are all important components to the identification of hereditary cancer syndromes in the oncology clinic.     

A systematic review of risk-reducing cancer surgery outcomes for hereditary cancer syndromes

Cancer predisposition genes are rare mutations that confer a high risk of cancer. For many hereditary cancer syndromes, risk reducing surgery is the single most effective strategy for preventing cancer, but it is irreversible. It has recently attracted significant media attention, following celebrity endorsement, which has led to a perceived lack of ill-effect and guaranteed successful outcome by the general public. Given these high expectations for risk-reducing surgery, a systematic review was performed to evaluate the reported complications for patients undergoing risk-reducing surgery. A systematic review of MEDLINE, EMBASE, CINAHL, AMED and PubMed work was conducted using PRISMA for risk-reducing surgery in adults for cancer predisposition genes in breast, ovary, stomach, thyroid and colorectal. The main outcomes were 30-day morbidity and mortality associated with these procedures. Twenty-five studies (2366 patients) reporting on outcomes following risk-reducing surgery were analysed, 5 related to breast and/or ovary, 3 for stomach, 2 for thyroid and the remaining 15 were colorectal. Risk-reducing surgery was uniformly associated with 30-day morbidity, particularly for breast (variable rates), colorectal (311/1400 patients (22%)) and stomach (35/75 patients (47%)) surgery. The 30-day morbidity for ovarian risk-reducing surgery was relatively low (11/244 patients (5%)). There was also a small mortality risk associated with colorectal (1/1400 patients) and stomach (1/75 patients). This study provides an important and necessary summary of the current data, enabling clinicians to better inform patients of the associated short and long-term outcomes in risk-reducing surgery for cancer predisposition genes.     

The management of families affected by hereditary non-polyposis colorectal cancer (HNPCC)

This study assessed current practice and methods for improvement in the management of families with hereditary non-polyposis colorectal cancer (HNPCC). HNPCC families registered at five London Genetics Centres and a specialised Colorectal family cancer clinic (CFCC) were identified. Ascertainment of management and outcome details were obtained by scrutiny of patient records and by correspondence with General practitioners (GPs). Two hundred and three families with HNPCC were identified. 79.5% (403/507) of at-risk relatives ascertained were contacted by the genetics centres, and 80.2% (65/81) by the CFCC (P = 1.0). 54.8% (211/385) of probands and relatives within genetics centres’ catchment areas were advised to undertake a surveillance programme, compared with 82.1% (64/78) of those cared for by the CFCC (P < 4.2 × 10⁻⁶). Adherence to surveillance guidelines was 76.6% (49/64) in individuals cared for by the only centre that undertook responsibility for surveillance follow-up (CFCC) and 41.7% (88/211) for the genetics centres, which did not assume responsibility (P < 8.9 × 10⁻⁷) (using two sided P-values for P (O ≥ E|O ≤ E)). 15.3% of GPs were unaware their patient had been recommended a surveillance programme, 65% did not know who was responsible for ensuring surveillance follow-up. A questionnaire to fifteen UK genetics centres demonstrated that the majority (86.7%) did not assume responsibility for surveillance follow-up. Since surveillance adherence is clearly better where centres assume responsibility for follow-up, it is recommended that regional or national registers of HNPCC families be developed and maintained to ensure effective management.     

Awareness of gynecologic surveillance in women from hereditary non-polyposis colorectal cancer families

Objective To determine knowledge of gynecologic cancer risk and screening in women with HNPCC.Study design Forty-three women with HNPCC were counseled through a gastrointestinal cancer risk program, and later sent a questionnaire regarding their screening practices for gynecologic neoplasms.Results Twenty-seven (63%) of 43 responded. Fifteen (55%) of 27 had previously been diagnosed with cancer. Among 16 women with a uterus, 11 (69%) reported surveillance by ultrasound or endometrial sampling. Among 21 respondents with ovaries, 13 (62%) reported screening by ultrasound or CA125. Twenty-two (81%) of 27 had seen a gynecologist after receiving their HNPCC diagnosis, but only 12% recalled hearing about risks from their gynecologist, and␣8% from their gynecologic oncologist. Genetic counselors were cited as the most common source (48%) of gynecologic cancer risk information.Conclusions While the effectiveness of surveillance remains in question, gynecologists can be a source of information regarding gynecologic cancer risk for women from HNPCC families.Presented at the 10th Biennial International Gynecologic Cancer Society Meeting, October 3–7, 2004, Edinburgh, Scotland     

Hereditary colorectal cancer syndromes

The purpose of this article is to review the genetic colorectal cancer syndromes including Hereditary Nonpolyposis Colorectal Cancer (HNPCC), Family Polyposis (FAP) and the hamartomatous polyposis syndromes. HNPCC is the most common of the hereditary colorectal cancer syndromes, and is the result of defects in the mismatch repair genes. Individuals with HNPCC have an 80 lifetime risk of colorectal cancer, and in females a 30–50% risk of endometrial cancer, as well as predisposition for a number of other malignancies. Early screening and interval surveillance for colorectal and endometrial cancer are recommended. In FAP, mutations in the Adenomatous Polyposis Coli (APC) tumor suppressor gene give rise to hundreds to thousands of colorectal polyps, some of which will inevitably progress to cancer. Early diagnosis and timely prophylactic colectomy prevent this outcome. Chemoprevention with nonsteroidal anti-inflammatory drugs can reduce adenoma number and size in FAP, but the effect is incomplete. In addtion, surveillance for upper gastrointestinal tract malignancies is necessary. Attenuated forms of FAP may be the result of mutations in the APC gene, or in the recently described MYH gene. Mutations in the MYH gene should be considered in individuals with multiple adenomas whose family history does not reflect an autosomal dominant pattern of inheritance. The hamartomatous polyposis syndromes are uncommon but distinctive disorders in which multiple hamartomatous polyps develop at a young age. Our understanding of the genetic basis of these disorders is improving, and a predisposition for gastrointestinal and other malignancies has recently been recognized. This article summarizes the genetics, clinical manifestations and clinical management of each of these syndromes with an emphasis on genetic testing and prevention.     

Sarcomas associated with hereditary nonpolyposis colorectal cancer: broad anatomical and morphological spectrum

Hereditary nonpolyposis colorectal cancer (HNPCC) is primarily linked to colorectal and endometrial cancer, but is associated with a broad tumor spectrum. Though not formally part of the syndrome, occasional sarcomas have been reported in individuals with HNPCC. We used the national Danish HNPCC-register to identify HNPCC families in which sarcomas had been diagnosed. Fourteen sarcomas were identified in families with mutations in MSH2, MSH6, and MLH1. The median age at sarcoma diagnosis was 43 (15–74) years. Soft tissue sarcomas predominated followed by uterine sarcomas and eight histopathological subtypes were represented with recurrent diagnoses of liposarcoma, leiomyosarcoma, and carcinosarcoma. Tumor tissue from eight cases was available for analysis of mismatch-repair (MMR) status using immunohistochemical staining and analysis of microsatellite instability, which revealed MMR defects in six of the eight tumors investigated. This suggests that sarcomas may be part of the HNPCC tumor spectrum and that colorectal cancer should be considered in the family history of sarcoma patients.     

The added value of PMS2 immunostaining in the diagnosis of hereditary nonpolyposis colorectal cancer

Identification and characterization of the genetic background in patients with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome is important since control programmes can in a cost-effective manner prevent cancer development in high-risk individuals. HNPCC is caused by germline mismatch repair (MMR) gene mutations and the genetic analysis of HNPCC therefore includes assessment of microsatellite instability (MSI) and immunohistochemical MMR protein expression in the tumor tissue. MSI is found in >95% of the HNPCC-associated tumors and immunostaining using antibodies against the MMR proteins MLH1, MSH2, and MSH6 has been found to correctly pinpoint the affected gene in about 90% of the cases. The PMS2 antibody was the most recently developed and we have in a clinical material assessed the added value of PMS2 immunostaining in 213 patients with suspected hereditary colorectal cancer. All 119 MSS tumors showed retained expression for all four antibodies and PMS2 did thus not identify any underlying MMR defect in these cases. However, PMS2 immunostaining contributed to the characterization of the MMR defect in a subset of the MSI tumors. Concomitant loss of MLH1 and PMS2, which functionally interact in the MutLα complex, was found in 98% of the tumors from patients with germline MLH1 mutations. Among the 12 MSI-high tumors with retained expression of MLH1, MSH2 and MSH6, 8 tumors showed loss of PMS2 staining, and mutations in MLH1 were identified in 2 and mutations in PMS2 in 3 of these individuals. In summary, isolated loss of PMS2 was found in 8% of the MSI-high tumors in our series, including 8/12 previously unexplained MSI-high tumors, in which mutations either in MLH1 or in PMS2 were identified in five cases.     

The importance of genetics for timing and extent of surgery in inherited colorectal cancer syndromes

Approximately 5% of colorectal cancers arise within an inherited colorectal cancer syndrome, with known underlying genetic etiologies. These syndromes increase the risk of colorectal and extracolonic cancers. Identification of a specific genetic pathogenic variant defines the syndrome, and quantifies the elevated risks compared to the general population. Thus, knowing and understanding the risks associated with each pathogenic variant allows for risk-stratification and a more individualized management strategy. These factors influence both the timing of surgery and the extent of colorectal surgery for patients with these syndromes. Familial Adenomatous Polyposis (FAP) is a dominantly inherited polyposis syndrome caused by pathogenic variant in the APC gene and results in a near 100% chance of developing colorectal cancer if not treated. There is a genotype-phenotype correlation in which the affected gene locus is associated with severity of polyposis and the risk of desmoid disease. Prophylactic surgery ranging from total abdominal colectomy or total proctocolectomy is recommended before cancer develops. Lynch syndrome is a non-polyposis inherited syndrome caused by a pathogenic variant in MLH1, MSH2, MSH6, or PMS2. Although prophylactic colectomy in Lynch syndrome is uncommon, total abdominal colectomy as prophylaxis in the setting of colon cancer is recommended due to the likelihood of metachronous colorectal cancer. This article reviews the role of genetics surgical decision making with respect to the timing and extent of surgery within the hereditary colorectal cancer syndromes.     

Hereditary cancer syndromes

Hereditary cancer syndromes(HCSs) are arguably the most frequent category of Mendelian genetic diseases, as at least 2% of presumably healthy subjects carry highly-penetrant tumor-predisposing pathogenic variants(PVs). Hereditary breast-ovarian cancer and Lynch syndrome make the highest contribution to cancer morbidity; in addition, there are several dozen less frequent types of familial tumors. The development of the majority albeit not all hereditary malignancies involves two-hit mechanism, i....