Risk of urothelial bladder cancer in Lynch syndrome is increased, in particular among MSH2 mutation carriers

Lynch syndrome and urologic malignancies: a contemporary review

PURPOSE OF REVIEW

An overview of urologic malignancies in Lynch syndrome and the current state of research.

RECENT FINDINGS

Upper tract urothelial carcinoma (UTUC) is the third most common malignancy in Lynch syndrome. Establishment and utilization of a sensitive and practical screening method for Lynch syndrome in patients presenting with UTUC is overdue. Next-generation sequencing to evaluate for microsatellite instability (MSI) and detect mutations of mismatch repair (MMR) genes may be the future of Lynch syndrome screening. Epidemiologic data and molecular characterization suggest bladder urothelial carcinoma (BUC) and prostate cancer (PCA) as unrecognized components of Lynch syndrome. Small studies suggest that Lynch syndrome may predispose individuals to adrenocortical carcinoma. Testicular cancer literature focuses on characterizing MSI and MMR gene expression as it relates to chemotherapy sensitivity; outcomes suggest a potential avenue to investigate its relationship to Lynch syndrome.

SUMMARY

Patients with Lynch syndrome have an increased risk of urologic malignancies, including UTUC and likely BUC and PCA. BUC and PCA have a lower penetrance than UTUC for unknown reasons. Established Lynch syndrome-associated genitourinary tumors will necessitate the development of methods to diagnose Lynch syndrome in patients presenting with these malignancies, in addition to establishing screening guidelines for patients with Lynch syndrome-associated genitourinary tumors.

Epidemiology of Bladder Cancer

Based on the latest GLOBOCAN data, bladder cancer accounts for 3% of global cancer diagnoses and is especially prevalent in the developed world. In the United States, bladder cancer is the sixth most incident neoplasm. A total of 90% of bladder cancer diagnoses are made in those 55 years of age and older, and the disease is four times more common in men than women. While the average 5-year survival in the US is 77%, the 5-year survival for those with metastatic disease is a measly 5%. The strongest risk factor for bladder cancer is tobacco smoking, which accounts for 50-65% of all cases. Occupational or environmental toxins likewise greatly contribute to disease burden (accounting for an estimated 20% of all cases), though the precise proportion can be obscured by the fact bladder cancer develops decades after exposure, even if the exposure only lasted several years. Schistosomiasis infection is the common cause of bladder cancer in regions of Africa and the Middle East and is considered the second most onerous tropical pathogen after malaria. With 81% of cases attributable to known risk factors (and only 7% to heritable mutations), bladder cancer is a prime candidate for prevention strategies. Smoking cessation, workplace safety practices, weight loss, exercise and schistosomiasis prevention (via water disinfection and mass drug administration) have all been shown to significantly decrease the risk of bladder cancer, which poses a growing burden around the world.

[Immunohistochemical study of the MSI phenotype of urothelial bladder cancer]

OBJECTIVE

To investigate the MSI phenotype of urothelial bladder cancer (BC) by immunohistochemistry (IHC) and to assess its relationship to the prognostic factors of the disease and PD-L1 status of BC.

MATERIAL AND METHODS

Using the surgical and biopsy materials obtained from 50 patients with BC during examination and treatment, the investigators studied the MSI phenotype by IHC. A system was proposed to assess the IHC expression of MSI proteins, by taking into account the intensity of nuclear staining and the area occupied by tumor cells with stained nuclei.

RESULTS

An analysis of the results of an IHG study of MSI protein expression revealed a high direct correlation between the nuclear staining intensity of tumor cells and the percentage of tumor area occupied by the latter. The lack/decrease of the expression of the studied proteins was associated with the stage (T) and the presence of a high-grade tumor. The heterogeneous expression of the studied proteins (PMS2, MLH1, and MSH6) was noted to be 10, 30, and 40%, respectively.

CONCLUSION

A high direct correlation was observed between the nuclear staining intensity of tumor cells and the percentage of the area occupied by the latter. There was a relationship between the lack and/or decrease of the expression of MSI proteins (mainly PMS2 and MLH1 and to a lesser extent MSH6) and the grade of BC, as well as stage T; there was a tendency to decrease the expression of the studied proteins in the area of invasive tumor growth, which confirms the prognostic role of MSI proteins. The most pronounced heterogeneity of IHC expression was noted with MSH6; the least one was seen with PMS2. There was a predominance of high-grade surface carcinomas (T1) among the heterogeneously stained tumors. In the case of positive PD-L1 status, there was decreased PMS2 and MLH1 expression and pronounced MSH6 expression; no significant relationship was found due to the small number of these cases. The authors consider it necessary to conduct further studies of the relationship between the MSI phenotype and the PD-L1 status of BC.

Cancer Susceptibility Mutations in Patients With Urothelial Malignancies

PURPOSE

Urothelial cancers (UCs) have a substantial hereditary component, but, other than their association with Lynch syndrome, the contribution of genetic risk factors to UC pathogenesis has not been systematically defined. We sought to determine the prevalence of pathogenic/likely pathogenic (P/LP) germline variants in patients with UC and identify associated clinical factors.

PATIENTS AND METHODS

Overall, 586 patients with UC underwent prospective, matched tumor-normal DNA sequencing. Seventy-seven genes associated with cancer predisposition were analyzed; allele frequencies were compared with publicly available database.

RESULTS

P/LP germline variants were identified in 80 (14%) of 586 individuals with UC. The most common P/LP variants in high- or moderate-penetrance genes were BRCA2 (n = 9; 1.5%), MSH2 (n = 8; 1.4%), BRCA1 (n = 8; 1.4%), CHEK2 (n = 6; 1.0%), ERCC3 (n = 4; 0.7%), and NBN and RAD50 (n = 3; 0.5% each). Sixty-six patients (83%) had germline P/LP variants in DNA-damage repair (DDR) genes, of which 28 (42%) had biallelic inactivation. Patients with P/LP variants were more commonly diagnosed at an early age (22% v 6% in those without variants; P = .01). BRCA2 and MSH2 were significantly associated with an increased risk for UC (odds ratio, 3.7 [P = .004] and 4.6 [P = .001], respectively). Current clinical guidelines for referral for genetic testing failed to identify 6 (26%) patients with high-penetrance variants.

CONCLUSION

Clinically significant P/LP germline variants in DDR genes frequently are present in patients with advanced UC. The presence of DDR germline variants could guide cancer screening for patients and their families and serve as predictive biomarkers of response to targeted or immunotherapies. Family history-based criteria to identify patients with hereditary UC susceptibility are insensitive. Broader germline testing in UC, particularly in those of young ages, should be considered.

Development and Validation of a 34-Gene Inherited Cancer Predisposition Panel Using Next-Generation Sequencing

The use of genetic testing to identify individuals with hereditary cancer syndromes has been widely adopted by clinicians for management of inherited cancer risk. The objective of this study was to develop and validate a 34-gene inherited cancer predisposition panel using targeted capture-based next-generation sequencing (NGS). The panel incorporates genes underlying well-characterized cancer syndromes, such as BRCA1 and BRCA2 (BRCA1/2), along with more recently discovered genes associated with increased cancer risk. We performed a validation study on 133 unique specimens, including 33 with known variant status; known variants included single nucleotide variants (SNVs) and small insertions and deletions (Indels), as well as copy-number variants (CNVs). The analytical validation study achieved 100% sensitivity and specificity for SNVs and small Indels, with 100% sensitivity and 98.0% specificity for CNVs using in-house developed CNV flagging algorithm. We employed a microarray comparative genomic hybridization (aCGH) method for all specimens that the algorithm flags as CNV-positive for confirmation. In combination with aCGH confirmation, CNV detection specificity improved to 100%. We additionally report results of the first 500 consecutive specimens submitted for clinical testing with the 34-gene panel, identifying 53 deleterious variants in 13 genes in 49 individuals. Half of the detected pathogenic/likely pathogenic variants were found in BRCA1 (23%), BRCA2 (23%), or the Lynch syndrome-associated genes PMS2 (4%) and MLH1 (2%). The other half were detected in 9 other genes: MUTYH (17%), CHEK2 (15%), ATM (4%), PALB2 (4%), BARD1 (2%), CDH1 (2%), CDKN2A (2%), RAD51C (2%), and RET (2%). Our validation studies and initial clinical data demonstrate that a 34-gene inherited cancer predisposition panel can provide clinically significant information for cancer risk assessment.

Prevalence of pathogenic germline cancer risk variants in high-risk urothelial carcinoma

Purpose

To date, there has not been a large, systematic evaluation of the prevalence of germline risk variants in urothelial carcinoma (UC).

Methods

We evaluated the frequency of germline pathogenic and likely pathogenic variants in 1038 patients with high-risk UC who underwent targeted clinical germline testing. Case–control enrichment analysis was performed to screen for pathogenic variant enrichment in 17 DNA repair genes in 1038 UC patients relative to cancer-free individuals.

Results

Among 1038 patients with UC, the cumulative frequency of patients with pathogenic variants was 24%; 18.6% of patients harbored ≥1 actionable germline variant with preventive or therapeutic utility. MSH2 (34/969, 3.5%) and BRCA1/2 (38/867, 4.4%) germline variants had the highest frequency. Germline variants in DNA damage repair genes accounted for 78% of pathogenic germline variants. Compared to the cancer-free cohort, UC patients had significant variant enrichment in MSH2 (odds ratio [OR]: 15.4, 95% confidence interval [CI]: 7.1–32.7, p < 0.0001), MLH1 (OR: 15.9, 95% CI: 4.4–67.7, p < 0.0001), BRCA2 (OR: 5.7, 95% CI: 3.2–9.6, p < 0.0001), and ATM (OR: 3.8, 95% CI: 1.8–8.3, p = 0.02).

Conclusion

In this study, 24% of UC patients harbored pathogenic germline variants and 18.6% had clinically actionable variants. MLH1 and MSH2 were validated as UC risk genes while ATM and BRCA2 were highlighted as potential UC predisposition genes. This work emphasizes the utility of germline testing in selected high-risk UC cohorts.

Advancements in the clinical management of upper tract urothelial carcinoma

Introduction: Upper tract urothelial carcinoma (UTUC) remains a complex disease to manage given challenges in staging, surgical resection, use of perioperative therapy, and prevention of bladder recurrences. High-level evidence is limited to guide management; however, recent data have shifted treatment paradigms. We intend to review recent evidence on advancements in the clinical management for UTUC.Areas covered: This review summarizes advancements in pre-operative work-up, surgical technique, and the use of intravesical and systemic therapy in both the neoadjuvant and adjuvant settings. Special comment is made on progress in the genomics of UTUC and how that can inform clinical practice.Expert opinion: Advancements in the clinical management of UTUC are most prominently being made in the neoadjuvant chemotherapy setting. Although level I evidence is sparse, data from both single and multi-institutional retrospective studies strongly encourage the use of neoadjuvant chemotherapy especially in high-risk or advanced-stage patients.

Clinical Factors Associated with Urinary Tract Cancer in Individuals with Lynch Syndrome

BACKGROUND

Lynch syndrome confers markedly increased risks of various malignancies, including urinary tract cancers (UTC; renal pelvis, ureter, bladder, and possibly kidney cancers). It is unknown how to determine which Lynch syndrome carriers are at highest UTC risk. Our aim was to identify clinical factors associated with UTC among Lynch syndrome carriers.

METHODS

The study population was a cohort of 52,758 consecutively ascertained individuals undergoing Lynch syndrome testing at a commercial laboratory. Clinical data were obtained from test request forms completed by the ordering provider. Univariate analysis and multivariate logistic regression were performed to identify factors associated with UTC among Lynch syndrome carriers.

RESULTS

Compared with noncarriers, Lynch syndrome carriers were significantly more likely to have had UTC (4.1% vs. 1.2%; P < 0.0001). Lynch syndrome-associated UTC was independently associated with male sex [OR 1.95; 95% confidence interval (CI), 1.38-2.76], increased age (OR 2.44 per 10 years; 95% CI, 2.11-2.82), familial burden of UTC (OR 2.69 per first-/second-degree relative with UTC; 95% CI, 1.99-3.63), and pathogenic EPCAM/MSH2 variants (OR 4.01; 95% CI, 2.39-6.72) but not MLH1 variants (OR 1.17; 95% CI, 0.63-2.17), race, or history of other Lynch syndrome-associated malignancy. A total of 143 of 158 (90.5%) Lynch syndrome carriers with UTC had ≥1 of the following characteristics: male sex, EPCAM/MSH2 variants, or family history of UTC; 1,236 of 1,251 (98.8%) Lynch syndrome carriers lacking all of these characteristics had no history of UTC.

CONCLUSIONS

Specific clinical factors can reliably identify Lynch syndrome carriers most likely to be at risk for UTC.

IMPACT

A predictable subset of Lynch syndrome carriers may be most likely to benefit from UTC surveillance/prevention.

Genomic characterization for familial cases with urothelial carcinoma

In this report, we present familial cases of urothelial carcinoma. To investigate the possibility of hereditary urothelial cancer, we performed semiconductor-based next-generation DNA sequencing. A woman in her 80s who had bladder and left ureteral cancer was hospitalized in Sapporo Shirakaba-dai Hospital due to consciousness disturbance. Radiographic evaluation revealed multiple liver metastases and she died 38 days later. Needle necropsy was done for a left ureteral tumor that continued to her bladder tumor and for liver metastases. At the same time, her son in his 60s, who also had muscle-invasive bladder cancer, was admitted to Sapporo Medical University Hospital and underwent neoadjuvant chemotherapy followed by laparoscopic radical cystectomy. DNA was isolated from both cancers and normal controls in each case and analyzed by massive parallel sequencing of 409 cancer-related genes using a targeted, multiplex PCR approach followed by semiconductor sequencing. Somatic mutations of KMT2C and KMT2D were detected in the mother's tumor. Copy number gains of FGFR1, IkBKB, NFkB2, FGFR2, and FLT3 and copy number losses of IGF2R and TP53 were also found in her cancer. In her son's tumor, somatic mutations of FGFR3 and EP300 were identified. Copy number gains of IkBKE/MAPK1/PARP1, EGFR, BRAF, IRS2, MAPK2K1, IGF1R, and ERBB2 and copy number loss of TP53 were also found in his cancer. There were no germline gene mutations related to familial urothelial carcinoma. Although somatic mutation of TP53 was a common feature, these cases with urothelial carcinoma might not be the result of a heredity syndrome.

Confirmation of damaging effect of MSH2 c.2634+1G>C mutation on splicing, its classification and implications for counseling

INTRODUCTION

Lynch syndrome (LS) is predisposing mainly to colorectal and endometrial carcinomas, but also to urinary tract cancers. LS association with upper urinary tract carcinomas is known, but its association with bladder cancer is not so clear. Confirmation of pathogenicity of detected mutations in LS-associated genes is required for adequate counseling.

MATERIAL AND METHODS

Tested young female has family history of two early colorectal and two bladder carcinomas. NGS sequencing revealed MSH2 splice site mutation c.2634+1G>C, which was confirmed by Sanger sequencing. MSH2 cDNA part containing potential splicing change was sequenced. in silico softwares were used to predict the effect of detected mutation on splicing and protein structure. ACMG Guidelines were used for mutation classification.

RESULTS

in silico softwares predict damaging effect of detected mutation on splicing and loss of protein-binding domains. cDNA sequencing confirmed this mutation causes exon 15 excision. ACMG Guidelines classify this mutation as Pathogenic.

DISCUSSION

MSH2 c.2634+1G>C mutation was not reported previously as LS associated. We confirmed its damaging effect on splicing. in silico tools predict consequent loss of protein domains implicating disrupted protein function. Our results suggest that this mutation should be classified as Pathogenic, and indicate inclusion of bladder cancer in LS cancer spectrum.

Familial Cancer Clustering in Urothelial Cancer: A Population-Based Case-Control Study

Background

Family history of bladder cancer confers an increased risk for concordant and discordant cancers in relatives. However, previous studies investigating this relationship lack any correction for smoking status of family members. We conducted a population-based study of cancer risks in relatives of bladder cancer patients and matched controls with exclusion of variant subtypes to improve the understanding of familial cancer clustering.

Methods

Case subjects with urothelial carcinoma were identified using the Utah Cancer Registry and matched 1:5 to cancer-free controls from the Utah Population Database. Cox regression was used to determine the risk of cancer in first-degree relatives, second-degree relatives, first cousins, and spouses. A total of 229 251 relatives of case subjects and 1 197 552 relatives of matched control subjects were analyzed. To correct for smoking status, we performed a secondary analysis excluding families with elevated rates of smoking-related cancers. All statistical tests were two-sided.

Results

First- and second-degree relatives of case subjects had an increased risk for any cancer diagnosis (hazard ratio [HR] = 1.06, 95% confidence interval [CI] = 1.03 to 1.09, P < .001; HR = 1.04, 95% CI = 1.02 to 1.07, P = .001) and urothelial cancer (HR = 1.73, 95% CI = 1.50 to 1.99, P < .001; HR = 1.35, 95% CI = 1.21 to 1.51, P < .001). Site-specific analysis found increased risk for bladder (HR = 1.69, 95% CI = 1.47 to 1.95, P < .001), kidney (HR = 1.30, 95% CI = 1.08 to 1.57, P = .006), cervical (HR = 1.25, 95% CI = 1.06 to 1.49, P = .01), and lung cancer (HR = 1.34, 95% CI = 1.19 to 1.51, P < .001) in first-degree relatives. Second-degree relatives had increased risk for bladder (HR = 1.35, 95% CI = 1.2 to 1.5, P < .001) and thyroid cancer (HR = 1.18, 95% CI = 1.03 to 1.35, P = .02). Spouses showed an increased risk for laryngeal (HR = 2.68, 95% CI = 1.02 to 7.05, P = .04) and cervical cancer (HR = 1.57, 95% CI = 1.13 to 2.17, P = .007). These results did not substantively change after correction for suspected smoking behaviors.

Conclusion

Our results suggest familial urothelial cancer clustering independent of smoking, with increased risk in relatives for both concordant and discordant cancers, suggesting shared genetic or environmental roots. Identifying families with statistically significant risks for non-smoking-related urothelial cancer would be extremely informative for genetic linkage studies.

Molecular and histopathology directed therapy for advanced bladder cancer

Bladder cancer is a heterogeneous group of tumours with at least 40 histological subgroups. Patients with localized disease can be cured with surgical resection or radiotherapy, but such curative options are limited in the setting of recurrent disease or distant spread, in which case systemic therapy is used to control disease and palliate symptoms. Cytotoxic chemotherapy has been the mainstay of treatment for advanced bladder cancer, but high-quality evidence is lacking to inform the management of rare subgroups that are often excluded from studies. Advances in molecular pathology, the development of targeted therapies and the resurgence of immunotherapy have led to the reclassification of bladder cancer subgroups and rigorous efforts to define predictive biomarkers for cancer therapies. In this Review, we present the current evidence for the management of conventional, variant and divergent urothelial cancer subtypes, as well as non-urothelial bladder cancers, and discuss how the integration of genomic, transcriptomic and proteomic characterization of bladder cancer could guide future therapies.

Heterogenous loss of mismatch repair (MMR) protein expression: a challenge for immunohistochemical interpretation and microsatellite instability (MSI) evaluation

Immunohistochemistry (IHC) for mismatch repair (MMR) proteins is used to identify MMR status: being diffusely positive (intact/retained nuclear staining) or showing loss of nuclear tumour staining (MMR protein deficient). Four colonic adenocarcinomas and a gastric adenocarcinoma with associated dysplasia that displayed heterogenous IHC staining patterns in at least one of the four MMR proteins were characterised by next‐generation sequencing (NGS). In order to examine a potential molecular mechanism for these staining patterns, the respective areas were macrodissected, analysed for microsatellite instability (MSI) and investigated by NGS and multiplex ligation‐dependent probe amplification (MLPA) analysis of MLH1, MSH2, MSH6 and PMS2 genes, including MLH1 methylation analysis. One colonic adenocarcinoma showed heterogenous MSH6 IHC staining and molecular analysis demonstrated increasing allelic burden of two MSH6 frameshift variants (c.3261delC and c.3261dupC) in areas with MSH6 protein loss compared to areas where MSH6 was retained. Two colonic adenocarcinomas with heterogenous MLH1 staining showed no differences in sequence variants. In one of these cases, however, MLH1 was hypermethylated in the area of MLH1 loss. Another colon carcinoma with heterogenous PMS2 staining (but with retained MSH6) showed both MSH6 c.3261dupC and 3260_3261dupCC where PMS2 protein was lost and only c.3261dupC where PMS2 was retained. The gastric carcinoma showed complete loss of MSH6 in dysplastic foci, while the underlying invasive carcinoma showed retention of MSH6. Both these areas, however, were MSI‐high and showed the same MSH6 variant: c.3261delC. The gastric dysplasia additionally showed MSH6 c.3261dupC. In four of the five cases where MMR protein was lost, these areas were MSI‐high. Heterogenous MMR IHC (focal and/or zonal within the same tumour or between invasive and dysplastic preinvasive areas) is not always due to artefact and is invariably related to MSI‐high status in the areas of loss. An interesting aspect to this study is the presence of MSH6 somatic mutations irrespective of whether MSH6 IHC staining was intact or lost.

Recent advances in upper tract urothelial carcinomas: From bench to clinics

Urothelial carcinoma in the upper tract is rare and often discussed separately. Many established risk factors were identified for the disease, including genetic and external risk factors. Radiographic survey, endoscopic examination and urine cytology remained the most important diagnostic modalities. In localized upper tract urothelial carcinomas, radical nephroureterectomy with bladder cuff excision are the gold standard for large, high-grade and suspected invasive tumors of the renal pelvis and proximal ureter, whereas kidney-sparing surgeries should be considered in patients with low-risk disease. Advances in technology have given endoscopic surgery an important role, not only in diagnosis, but also in treatment. Although platinum-based combination chemotherapy is efficacious in advanced or metastatic disease, current established chemotherapy regimens are toxic and lack a sustained response. Immune checkpoint inhibitors have led to a new era of treatment for advanced or metastatic urothelial carcinomas. The remarkable results achieved thus far show that immunotherapy will likely be the future treatment paradigm. The combination of immune checkpoint inhibitors and other agents is another inspiring avenue to explore that could benefit even more patients. With respect to the high incidence rate and different clinical appearance of upper tract urothelial carcinomas in Taiwan, a possible correlation exists between exposure to certain external risk factors, such as arsenic in drinking water and aristolochic acid in Chinese herbal medicine. As more gene sequencing differences between upper tract urothelial carcinomas and various disease causes are detailed, this has warranted the era of individualized screening and treatment for the disease.

A retrospective study of extracolonic, non-endometrial cancer in Swedish Lynch syndrome families

Background

Lynch Syndrome is an autosomal dominant cancer syndrome caused by pathogenic germ-line variants in one of the DNA-mismatch-repair (MMR) genes MLH1, MSH2, MSH6 or PMS2. Carriers are predisposed to colorectal and endometrial cancer, but also other cancer types. The purpose of this retrospective study was to characterize the tumour spectrum of the Swedish Lynch syndrome families.

Methods

Data were obtained from genetically verified 235 Lynch families from five of the six health care regions in Sweden. The material was stratified for gender, primary cancer, age and mutated gene and the relative proportions of specific cancer types were compared to those in the general population.

Results

A total of 1053 family members had 1493 cancer diagnoses of which 1011 were colorectal or endometrial cancer. Individuals with pathogenic variants in MLH1 and MSH2 comprised 78% of the cohort. Among the 482 non-colorectal/non-endometrial cancer diagnoses, MSH2 carriers demonstrated a significantly increased proportion of urinary tract, gastric, small bowel, ovarian and non-melanoma skin cancer compared to the normal population. MLH1 carriers had an elevated proportion of gastrointestinal cancers (gastric, small bowel, pancreas), while MSH6 carriers had more ovarian cancer than expected. Gastric cancer was predominantly noted in older generations.

Conclusion

Lynch syndrome confers an increased risk for multiple cancers other than colorectal and endometrial cancer. The proportions of other cancers vary between different MMR genes, with highest frequency in MSH2-carriers. Gender and age also affect the tumour spectrum, demonstrating the importance of additional environmental and constitutional parameters in determining the predisposition for different cancer types.

Systematic Review: An Update on the Spectrum of Urological Malignancies in Lynch Syndrome

Background:

Lynch syndrome is an autosomal dominant disorder that predisposes individuals affected to certain malignancies. Colon and endometrial cancers are the malignancies most highly associated with Lynch syndrome. However, growing body of evidence links Lynch syndrome to urological cancers.

Objective:

This review aims to clarify the type of urological malignancies that fall under the Lynch-associated cancer spectrum.

Methods:

Using PRISMA guidelines, a systematic search between January 1990 to February 2018, was conducted using the MEDLINE database with the application of the following MESH terms: colorectal neoplasms, hereditary nonpolyposis; DNA mismatch repair; urologic neoplasms; kidney pelvis; ureteral neoplasms; urinary bladder; carcinoma, transitional cell; prostatic neoplasms; testicular neoplasms.

Results:

Upper tract urothelial cancers are well established under the Lynch spectrum. Increasing evidence supports its association with prostate cancer. However, there is, inconclusive and limited evidence for an association with bladder and testicular cancer.

Conclusions:

The evidence underpinning certain urological malignancies associated with Lynch syndrome has expanded in recent years. Our review may assist in providing a summary of the current standing in literature. However, we recommend further investigations to better clarify associations, particularly with prostate, bladder and testicular cancer.

Molecular subtype classification of urothelial carcinoma in Lynch syndrome

Lynch syndrome confers an increased risk for urothelial carcinoma (UC). Molecular subtypes may be relevant to prognosis and therapeutic possibilities, but have to date not been defined in Lynch syndrome‐associated urothelial cancer. We aimed to provide a molecular description of Lynch syndrome‐associated UC. Thus, Lynch syndrome‐associated UCs of the upper urinary tract and the urinary bladder were identified in the Danish hereditary nonpolyposis colorectal cancer (HNPCC) register and were transcriptionally and immunohistochemically profiled and further related to data from 307 sporadic urothelial carcinomas. Whole‐genome mRNA expression profiles of 41 tumors and immunohistochemical stainings against FGFR3, KRT5, CCNB1, RB1, and CDKN2A (p16) of 37 tumors from patients with Lynch syndrome were generated. Pathological data, microsatellite instability, anatomic location, and overall survival data were analyzed and compared with sporadic bladder cancer. The 41 Lynch syndrome‐associated UC developed at a mean age of 61 years with 59% women. mRNA expression profiling and immunostaining classified the majority of the Lynch syndrome‐associated UC as urothelial‐like tumors with only 20% being genomically unstable, basal/SCC‐like, or other subtypes. The subtypes were associated with stage, grade, and microsatellite instability. Comparison to larger datasets revealed that Lynch syndrome‐associated UC shares molecular similarities with sporadic UC. In conclusion, transcriptomic and immunohistochemical profiling identifies a predominance of the urothelial‐like molecular subtype in Lynch syndrome and reveals that the molecular subtypes of sporadic bladder cancer are relevant also within this hereditary, mismatch‐repair defective subset.

Bladder Cancer Genetic Susceptibility. A Systematic Review

Background:

The variant/gene candidate approach to explore bladder cancer (BC) genetic susceptibility has been applied in many studies with significant findings reported. However, results are not always conclusive due to the lack of replication by subsequent studies.

Objectives:

To identify all epidemiological investigations on the genetic associations with BC risk, to quantify the likely magnitude of the associations by applying metaanalysis methodology and to assess whether there is a potential for publication/reporting bias.

Methods:

To address our aims, we have catalogued all genetic association studies published in the field of BC risk since 2000. Furthermore, we metaanalysed all polymorphisms with data available from at least three independent case-control studies with subjects of Caucasian origin analyzed under the same mode of inheritance.

Results:

The characterization of the genetic susceptibility of BC is composed of 28 variants, GWAS contributing most of them. Most of the significant variants associated with BC risk are located in genes belonging to chemical carcinogenesis, DNA repair, and cell cycle pathways. Causal relationship was also provided by functional analysis for GSTM1-null, NAT2-slow, APOBEC-rs1014971, CCNE1-rs8102137, SLC14A1-rs10775480, PSCA-rs2294008, UGT1A-rs1189203, and TP63-rs35592567.

Conclusions:

Genetic susceptibility of BC is still poorly defined, with GWAS contributing most of the strongest evidence. The systematic review did not provide evidence of further genetic associations. The potential public health translation of the existing knowledge on genetic susceptibility on BC is still limited.

Inherited forms of bladder cancer: a review of Lynch syndrome and other inherited conditions

Environmental factors that play a role in the urothelial carcinogenesis have been well characterized. Current research is continuously exploring potential heritable forms of bladder cancer. Lynch syndrome is a well-known inheritable disease that increases the risk for a variety of cancers, including urothelial carcinomas. Screening of patients with known Lynch syndrome is important to evaluate for development of new primary tumors. Further study may provide more information on what level of follow-up each patient needs. Recent data suggest that mismatch repair mutations confer a greater risk for urothelial cancer. Additional large patient series as well as advancement of molecular testing may provide triage for Lynch syndrome patients in regards to the frequency and type of screening best suited for individual patient.

Update on Screening for Urological Malignancies

Urological malignancies are a major source of morbidity and mortality in men over 40. Screening for those malignancies has a potential benefit of reducing both. However, even after more than two decades of screening for prostate cancer, the implications of most resulting information are still a matter of debate. Controversy extends over several aspects of prostate cancer screening programs, including age of onset, defining populations at risk, most appropriate intervals, as well as the optimal methods to be used for screening. The medical community is still divided regarding the effectiveness of prostate cancer-related death prevention and its benefits-to-harms ratio, reflecting an inconsistency regarding screening recommendations. Similarly, benefits of screening for urothelial and kidney tumors are yet lacking high-level evidence, although recent evidence supports screening of populations at risk. Clearly, the current era of evolving molecular and genetic biomarkers harbors the potential to change screening practice. In this paper, we review current guidelines as well as giving an update on new developments which might influence screening strategies in common urological malignancies.

Family history of cancer and the risk of bladder cancer: A case-control study from Italy

BACKGROUND

A family history of bladder cancer has been associated with the risk of bladder cancer, but quantification of the excess risk in different populations is still a relevant issue. Further, the role of a family history of other cancers on the risk of bladder cancer remains unclear.

METHODS

We analyzed data from an Italian case-control study, including 690 bladder cancer cases and 665 hospital controls. Odds ratios (ORs) were estimated through unconditional logistic regression models, adjusted for sex, age, study center, year of interview and further for education, smoking and sibling's number.

RESULTS

The OR for family history of bladder cancer was 2.13 (95% confidence intervals (95%CIs) 1.02-4.49) from the model with partial adjustment, and 1.99 (95%CI 0.91-4.32) after additional adjustment for smoking and siblings' number, based on 23 cases (3.3%) and 11 controls (1.7%) with a family history of bladder cancer. The fully adjusted OR was 3.77 when the relative was diagnosed at age below 65years. Smokers with a family history of bladder cancer had a four-fold increased risk compared to non-smokers without a family history. Bladder cancer risk was significantly increased among subjects with a family history of hemolymphopoietic cancers (OR=2.97, 95%CI 1.35-6.55). Family history of cancer at other sites showed no significant association with bladder cancer risk.

CONCLUSION

This study confirms an approximately two-fold increased risk of bladder cancer for family history of bladder cancer, and indicates a possible familial clustering of bladder cancer with cancers of the hemolymphopoietic system.

DNA Repair Pathway Alterations in Bladder Cancer

Most bladder tumors have complex genomes characterized by a high mutation burden as well as frequent copy number alterations and chromosomal rearrangements. Alterations in DNA repair pathways—including the double-strand break (DSB) and nucleotide excision repair (NER) pathways—are present in bladder tumors and may contribute to genomic instability and drive the tumor phenotype. DNA damaging such as cisplatin, mitomycin C, and radiation are commonly used in the treatment of muscle-invasive or metastatic bladder cancer, and several recent studies have linked specific DNA repair pathway defects with sensitivity to DNA damaging-based therapy. In addition, tumor DNA repair defects have important implications for use of immunotherapy and other targeted agents in bladder cancer. Therefore, efforts to further understand the landscape of DNA repair alterations in bladder cancer will be critical in advancing treatment for bladder cancer. This review summarizes the current understanding of the role of DNA repair pathway alterations in bladder tumor biology and response to therapy.

The risk of colorectal cancer is not increased after a diagnosis of urothelial cancer: a population-based study

BACKGROUND

The data about whether patients with a prior urothelial cancer (uca) are at increased risk of colorectal cancer (crc) are conflicting. We used a competing risks analysis to determine the risk of crc after uca.

METHODS

Historical cohorts were assembled by record linkage of Manitoba Cancer Registry and Manitoba Health databases. The incidence of crc for individuals with uca as their first cancer between 1987 and 2009 was compared with the incidence for randomly selected age-and sex-matched individuals without a cancer diagnosis at the index date (uca diagnosis date). Three competing outcomes (crc, another primary cancer, and death) were evaluated by competing risks proportional hazards models with adjustment for relevant confounders.

RESULTS

The cohorts of 4591 patients with uca and 22,312 without uca were followed for a total of 179,287 person-years (py). After uca, the rate of subsequent colon cancer in uca patients was 4.5 per 1000 py compared with 3.6 per 1000 py in the non-cancer cohort. In the multivariable analysis, no overall increase in crc risk was observed for patients first diagnosed with uca (hazard ratio: 0.88; 95% confidence interval: 0.70 to 1.1; p = 0.26).

CONCLUSIONS

Because of similar crc risk, a similar crc screening strategy should be applied for individuals with and without uca.

Upper tract urothelial carcinomas: frequency of association with mismatch repair protein loss and lynch syndrome

Increased risk for upper tract urothelial carcinoma is described in patients with Lynch syndrome, caused by germline mutations in mismatch repair genes. We aimed to identify the frequency of mismatch repair protein loss in upper tract urothelial carcinoma and its potential for identifying an association with Lynch syndrome. We queried our database to identify upper tract urothelial carcinomas. Patients were cross-referenced for history of colorectal carcinoma or other common Lynch syndrome-associated neoplasms to enrich for potential Lynch syndrome cases. Tumor histopathologic characteristics were reviewed and each case was analyzed for loss of mismatch repair proteins, MLH1, MSH2, MSH6, and PMS2, by immunohistochemistry. Of 444 patients with upper tract urothelial carcinoma, a subset of 215 (encompassing 30 with upper tract urothelial carcinoma and another common Lynch syndrome-associated neoplasm) was analyzed for loss of mismatch repair protein expression. Of 30 patients with Lynch syndrome-associated neoplasms, six had documented Lynch syndrome, including two with Muir-Torre syndrome. Mismatch repair protein loss was identified in 7% of total upper tract urothelial carcinomas and 30% of patients with Lynch syndrome-associated neoplasms (including all patients with Lynch syndrome/Muir-Torre syndrome). Of patients without history of Lynch syndrome-associated neoplasms, 5 of 184 (2.7%) had loss of mismatch repair protein expression. Twelve cases with mismatch repair protein loss demonstrated loss of MSH2 and MSH6, and 2 had isolated loss of MSH6. MLH1 and PMS2 expression were consistently retained. Although increased intratumoral lymphocytes, inverted growth, pushing tumor-stromal interface, and lack of nuclear pleomorphism were more commonly seen in cases with mismatch repair protein loss, only intratumoral lymphocytes and presence of pushing borders were statistically significant. MLH1 and PMS2 testing appear to have little utility in upper tract urothelial carcinoma; however, mismatch repair protein loss of MSH2 and/or MSH6 by immunohistochemistry seems relatively sensitive and specific for identifying patients with potential Lynch syndrome.

Pseudomyxoma peritonei of a mature ovarian teratoma caused by mismatch repair deficiency in a patient with Lynch syndrome: a case report

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare disease with an estimated incidence of 1-2 cases per million individuals per year. PMP is characterized by the accumulation of abundant mucinous or gelatinous fluid derived from disseminated tumorous cells. Most of the tumorous cells are originated from rupture of appendiceal neoplasms, but some are from the metastasis of cancer of the colon, ovary, fallopian tube, urachus, colorectum, gallbladder, stomach, pancreas, lung and breast. Although frequent mutations in KRAS and/or GNAS genes have been reported, precise molecular mechanism underlying PMP remains to be elucidated. It is of note that mucinous tumour is one of the frequent histological features of colorectal cancer (CRC) in Lynch syndrome (LS), an autosomal dominantly inherited disease caused by a germline mutation of the DNA mismatch repair (MMR) genes including human mutL homolog 1 (MLH1), human mutS homolog 2 (MSH2), human mutS homolog 6 (MSH6), and postmeiotic segregation increased 2 (PMS2). Therefore, typical LS-associated tumours show mismatch repair instability. Although LS patients are most strongly predisposed to CRC, PMPs from mucinous CRC have not been reported in LS patients.

CASE PRESENTATION

In this report, we report a case of PMP originating from an ovarian teratoma in a LS patient. The patient had surgical treatment of PMP arising from an ovarian teratoma at the age of 38 years, and later developed a transverse colon cancer at the age of 40. The patient's family history fulfilled the Amsterdam criteria, and genetic analysis of the peripheral leukocytes identified a germ line mutation in the MLH1 gene (MLH1 c.1546dupC p.Q516PfsX3). Interestingly, immunohistochemical staining showed that the expression of MLH1 was lost in the colon cancer as well as the ovarian teratoma. Consistent with the loss of MLH1 expression, both tumours showed high microsatellite instability (MSI-H).

CONCLUSION

This case suggested that LS patients may develop various types of tumours including ovarian PMP, and that mismatch repair deficiency may play a role in the development of PMP derived from, at least, a part of ovarian teratomas.

Genetic testing for Lynch syndrome: family communication and motivation

Current genetic counselling practice for Lynch syndrome (LS) relies on diagnosed index patients to inform their biological family about LS, referred to as the family-mediated approach. The objective of this study was to evaluate this approach and to identify factors influencing the uptake of genetic testing for LS. In 59 mutation carriers, 70 non carriers and 16 non-tested relatives socio-demographic characteristics, family communication regarding LS, experiences and attitudes towards the family-mediated approach and motivations for genetic testing, were assessed. The majority of all respondents (73 %) were satisfied with the family-mediated approach. Nevertheless, 59 % of the respondents experienced informing a family member and 57 % being informed by a family member as burdensome. Non-tested differed from tested respondents, in that they were younger, less closely related to the index patient and a lower proportion had children. The most important reasons for declining genetic testing were (1) anticipating problems with life insurance and mortgage, (2) being content with life as it is, and (3) not experiencing any physical complaints. In conclusion, the majority of respondents consider the current family-mediated information procedure acceptable, although the provision of information on LS by relatives may be burdensome. Special attention should be paid to communication of LS to more distant relatives.

Syndrome-Associated Tumors by Organ System

Certain tumors suggest the possibility of a patient harboring a genetic syndrome, particularly in children. Syndrome-associated tumors of the gastrointestinal tract, genitourinary tract, gynecologic tract, heart, lungs, brain, eye, endocrine organs, and hematopoietic system will be briefly discussed.

Lynch syndrome risk management

Lynch syndrome has been known as hereditary non-polyposis colorectal cancer (HNPCC), and it is a dominantly inherited cancer syndrome caused by genetic mutations in cell mismatch repair genes, often leading to digestive system and female reproductive system tumors. At present, there is a high misdiagnosis rate for Lynch syndrome. This paper reviews the latest progress in Lynch syndrome risk management with regards to its monitoring, surgical treatment, pharmaceutical treatment, life style improvement and screening.

Frequent mismatch-repair defects link prostate cancer to Lynch syndrome

BACKGROUND

A possible role for prostate cancer in Lynch syndrome has been debated based on observations of mismatch-repair defective tumors and reports of an increased risk of prostate cancer in mutation carriers. Potential inclusion of prostate cancer in the Lynch syndrome tumor spectrum is relevant for family classification, risk estimates and surveillance recommendations in mutation carriers.

METHODS

We used the population-based Danish HNPCC-register to identify all prostate cancers that developed in mutation carriers and in their first-degree relatives from 288 Lynch syndrome families. The tumors were evaluated for clinicopathologic features and mismatch-repair status, and the cumulative risk of prostate cancer was determined.

RESULTS

In total, 28 prostate cancers developed in 16 mutation carriers and in 12 first-degree relatives at a median age of 63 years. The majority of the tumors were high-grade tumors with Gleason scores 8-10. Prostate cancer was associated with mutations in MSH2, MLH1 and MSH6 with loss of the respective mismatch repair protein in 69 % of the tumors, though a MSI-high phenotype was restricted to 13 % of the tumors. The cumulative risk of prostate cancer at age 70 was 3.7 % (95 % CI: 2.3-4.9).

CONCLUSION

We provide evidence to link prostate cancer to Lynch syndrome through demonstration of MMR defective tumors and an increased risk of the disease, which suggests that prostate cancer should be considered in the diagnostic work-up of Lynch syndrome.

Mismatch repair deficiency testing in clinical practice

Lynch syndrome, an autosomal dominant inherited disorder, is caused by inactivating mutations involving DNA mismatch repair (MMR) genes. This leads to profound genetic instability, including microsatellite instability (MSI) and increased risk for cancer development, particularly colon and endometrial malignancies. Clinical testing of tumor tissues for the presence of MMR gene deficiency is standard practice in clinical oncology, with immunohistochemistry and PCR-based microsatellite instability analysis used as screening tests to identify potential Lynch syndrome families. The ultimate diagnosis of Lynch syndrome requires documentation of mutation within one of the four MMR genes (MLH1, PMS2, MSH2 and MSH6) or EPCAM, currently achieved by comprehensive sequencing analysis of germline DNA. In this review, the genetic basis of Lynch syndrome, methodologies of MMR deficiency testing, and current diagnostic algorithms in the clinical management of Lynch syndrome, are discussed.

Lynch syndrome in the 21st century: clinical perspectives

Lynch syndrome (LS) is the most common of all inherited cancer syndromes, associated with substantially elevated risks for colonic and extracolonic malignancies, earlier onset and high rates of multiple primary cancers. At the genetic level, it is caused by a defective mismatch repair (MMR) system due to presence of germline defects in at least one of the MMR genes- MLH1, MSH2, MSH6, PMS2 or EPCAM. An impaired MMR function during replication introduces infidelity in DNA sequence and leads to ubiquitous mutations at simple repetitive sequences (microsatellites), causing microsatellite instability (MSI). Although previously, clinicopathological criteria such as Amsterdam I/II and Revised Bethesda Guidelines were commonly used to identify suspected LS mutation carriers, there has been a recent push towards universally testing, especially in case of colorectal cancers (CRCs), through immunohistochemistry for expression of MMR proteins or through molecular tests (polymerase chain reaction, PCR) for MSI, in order to identify LS mutation carriers and subject them to genetic testing to ascertain the specific gene implicated. In this review, we have discussed the latest diagnostic strategies and the current screening and treatment guidelines for colonic and extracolonic cancers in clinically affected and at-risk individuals for LS.

Mismatch repair deficiency associated with complete remission to combination programmed cell death ligand immune therapy in a patient with sporadic urothelial carcinoma: immunotheranostic considerations

Background

Mismatch repair deficiency (MMRD) is a common pathway of malignant transformation accounting for approximately 15–20 % of human carcinogensis. It has been postulated that MMRD increases tumor antigenicity and highlights a role for immunotherapeutic approach MMR-deficient cancers. This strategy was pursued in a patient with upper tract urothelial carcinoma, and the results are reported here.

Case Presentation

Molecular profiling was performed using next generation DNA sequencing and (IHC) testing for MMR and PD-L1. A patient with sporadic, high grade urothelial carcinoma of the renal pelvis was found to have a hypermutator genotype with 73 mutations occurring amidst 62 known drivers of malignancy, and 340 VUS alterations. MMR deficiency phenotype was confirmed by the absence of MSH2 and MSH6 as well as deleterious mutations in these genes. IHC staining for programmed cell death ligand-1 [PD-L1] revealed 2+ staining in 80 % of cells. The patient gained access to combination immunotherapy trial utilizing MEDI4736 and MEDI0680 through a clinical trial. The patient achieved a prolonged, complete remission within two months and had no severe ill effects from the treatment.

Conclusion

Given their ability to generate neo-antigens, MMR-deficient cancers may be uniquely susceptible to immune checkpoint inhibitor strategies, including urothelial tract cancers. Screening for MMR deficient cancers has the potential to become a routine strategy for evaluating the role of PD-L1 inhibitors for patient with advanced disease. (Trial registration: Clinicaltrials.gov NCT00938834. Registered 13 July 2009)

A founder MLH1 mutation in Lynch syndrome families from Piedmont, Italy, is associated with an increased risk of pancreatic tumours and diverse immunohistochemical patterns

The MLH1 c.2252_2253delAA mutation was found in 11 unrelated families from a restricted area south-west of Turin among 140 families with mutations in the mismatch repair genes. The mutation is located in the highly conserved C-terminal region, responsible for dimerization with the PMS2 protein. Twenty-five tumour tissues from 61 individuals with the c.2252_2253delAA mutation were tested for microsatellite instability (MSI) and protein expression. We compared the clinical features of these families versus the rest of our cohort and screened for a founder effect. All but one tumours showed the MSI-high mutator phenotype. Normal, focal and lack of MLH1 staining were observed in 16, 36 and 48 % of tumours, respectively. PMS2 expression was always lost. The mutation co-segregated with Lynch syndrome-related cancers in all informative families. All families but one fulfilled Amsterdam criteria, a frequency higher than in other MLH1 mutants. This was even more evident for AC II (72.7 vs. 57.5 %). Moreover, all families had at least one colon cancer diagnosed before 50 years and one case with multiple Lynch syndrome-related tumours. Interestingly, a statistically significant (p = 0.0057) higher frequency of pancreatic tumours was observed compared to families with other MLH1 mutations: 8.2 % of affected individuals versus 1.6 %. Haplotype analysis demonstrated a common ancestral origin of the mutation, which originated about 1,550 years ago. The mutation is currently classified as having an uncertain clinical significance. Clinical features, tissue analysis and co-segregation with disease strongly support the hypothesis that the MLH1 c.2252_2253delAA mutation has a pathogenic effect.

ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes

This guideline presents recommendations for the management of patients with hereditary gastrointestinal cancer syndromes. The initial assessment is the collection of a family history of cancers and premalignant gastrointestinal conditions and should provide enough information to develop a preliminary determination of the risk of a familial predisposition to cancer. Age at diagnosis and lineage (maternal and/or paternal) should be documented for all diagnoses, especially in first- and second-degree relatives. When indicated, genetic testing for a germline mutation should be done on the most informative candidate(s) identified through the family history evaluation and/or tumor analysis to confirm a diagnosis and allow for predictive testing of at-risk relatives. Genetic testing should be conducted in the context of pre- and post-test genetic counseling to ensure the patient's informed decision making. Patients who meet clinical criteria for a syndrome as well as those with identified pathogenic germline mutations should receive appropriate surveillance measures in order to minimize their overall risk of developing syndrome-specific cancers. This guideline specifically discusses genetic testing and management of Lynch syndrome, familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, serrated (hyperplastic) polyposis syndrome, hereditary pancreatic cancer, and hereditary gastric cancer.

Low frequency of HNPCC-associated microsatellite instability and aberrant MMR protein expression in early-onset bladder cancer

OBJECTIVES

Recently, it was shown that patients with Lynch syndrome due to an MSH2 mutation are at increased risk for the development of bladder cancer. To further this discussion, we screened the largest investigated cohort of patients with early-onset bladder cancer for microsatellite instability (MSI) and mismatch repair (MMR) deficiency to determine a possible role of Lynch syndrome in young patients with bladder cancer.

METHODS

A total of 109 cases of bladder tumors from young patients (aged <45 years) were examined for MSI (Bethesda consensus panel). Expression of MMR proteins (hMLH1, hMSH2, and hMSH6) was evaluated by immunohistochemistry using a tissue microarray. Results were compared with a series of unselected consecutive bladder tumors (n = 95).

RESULTS

Regarding the frequency of MSI high (1% vs 0%) or abnormal expression of MMR proteins (2% vs 6.5%), no significant difference between the early-onset and unselected patient group was found.

CONCLUSIONS

In young patients with bladder tumors, MSI and defects in MMR protein expression were not more frequent than in a series of consecutive bladder tumors. Most bladder tumors in young patients are not to be attributed to Lynch syndrome.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-Society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3-6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3,4,5,6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

The genetic basis of Lynch syndrome and its implications for clinical practice and risk management

Lynch syndrome is the most common cause of hereditary colon cancer, and accounts for as much as 3% of all colon and endometrial cancers. The identification and management of individuals with Lynch syndrome have evolved over the past 20 years, yet the syndrome remains vastly underdiagnosed. It is important for clinicians to recognize individuals and families who are at risk in order to be able to manage them appropriately and reduce their morbidity and mortality from this condition. This review will touch on the history of Lynch syndrome, the current knowledge of genotype–phenotype correlations, the cancers associated with Lynch syndrome, and management of individuals who are gene carriers.