Cost-effectiveness of routine screening for Lynch syndrome in colorectal cancer patients up to 70 years of age.

PURPOSE: To assess the cost-effectiveness of routine Lynch syndrome (LS) screening among colorectal cancer (CRC) patients ≤70 years of age. METHODS: A population-based series of CRC patients ≤70 years of age was routinely screened for LS. We calculated life years gained (LYG) and incremental cost-effectiveness ratios (ICERs) for different age cutoffs and comparing age-targeted screening with the revised Bethesda guidelines. RESULTS: Screening 1,117 CRC patients identified 23 LS patients, of whom 7 were ≤50 years of age, 7 were 51-60, and 9 were 61-70. Additionally, 70 LS carriers were identified among relatives (14, 42, and 14 per age category). Screening amounted to 205.9 LYG or 43.6, 118.0, and 44.3 LYG per age category. ICERs were [euro ]4.226/LYG for screening CRC patients ≤60 years of age compared with those ≤50 years and [euro ]7.051/LYG for screening CRC patients ≤70 years compared with those ≤60 years. The revised Bethesda guidelines identified 70 of 93 (75%) LS carriers. The ICER for LS screening in CRC patients ≤70 years of age compared with the revised Bethesda guidelines was [euro ]7.341/LYG. All ICERs remained less than [euro ]13.000/LYG in one-way sensitivity analyses. CONCLUSION: Routine LS screening by analysis of microsatellite instability, immunohistochemistry, and MLH1 hypermethylation in CRC patients ≤70 years of age is a cost-effective strategy with important clinical benefits for CRC patients and their relatives.Genet Med 18 10, 966-973.

Somatic aberrations of mismatch repair genes as a cause of microsatellite-unstable cancers.

Lynch syndrome (LS) is caused by germline mutations in mismatch repair (MMR) genes, resulting in microsatellite-unstable tumours. Approximately 35% of suspected LS (sLS) patients test negative for germline MMR gene mutations, hampering conclusive LS diagnosis. The aim of this study was to investigate somatic MMR gene aberrations in microsatellite-unstable colorectal and endometrial cancers of sLS patients negative for germline MMR gene mutations. Suspected LS cases were selected from a retrospective Clinical Genetics Department diagnostic cohort and from a prospective multicentre population-based study on LS in The Netherlands. In total, microsatellite-unstable tumours of 40 sLS patients (male/female 20/20, median age 57 years) were screened for somatic MMR gene mutations by next-generation sequencing. In addition, loss of heterozygosity (LOH) of the affected MMR genes in these tumours as well as in 68 LS-associated tumours and 27 microsatellite-unstable tumours with MLH1 promoter hypermethylation was studied. Of the sLS cases, 5/40 (13%) tumours had two pathogenic somatic mutations and 16/40 (40%) tumours had a (likely) pathogenic mutation and LOH. Overall, LOH of the affected MMR gene locus was observed in 24/39 (62%) tumours with informative LOH markers. Of the LS cases and the tumours with MLH1 promoter hypermethylation, 39/61 (64%) and 2/21 (10%) tumours, respectively, demonstrated LOH. Half of microsatellite-unstable tumours of sLS patients without germline MMR gene mutations had two (likely) deleterious somatic MMR gene aberrations, indicating their sporadic origin. Therefore, we advocate adding somatic mutation and LOH analysis of the MMR genes to the molecular diagnostic workflow of LS.

Limited diagnostic value of microsatellite instability associated pathology features in colorectal cancer.

To determine the diagnostic test characteristics and inter-observer variation of pathology features for identifying high microsatellite instability (MSI-H) colorectal cancer (CRC). Six pathologists blindly evaluated 177 CRC for the presence of MSI-H associated pathology features. Inter-observer agreement was determined by using Kappa-statistics. In the first random 88/177 cases, mucinous carcinoma, tumor-infiltrating lymphocytes (TIL) and Crohns-like infiltrate (CLI) were the best discriminators between MSI-H and microsatellite stable CRC [OR 5.6 (95 % CI 1.7-19), 5.4 (1.8-17) and 3.5 (1.1-11), respectively], with high specificity (89-91 %). The sensitivities for MSI-H, however, were low (31-41 %). In addition, inter-observer agreement was moderate for TIL and CLI (κ 0.38 and 0.48, respectively), but very good for mucinous carcinoma (κ 0.86). Interpretation of overall histopathology as suggestive for MSI-H performed better than any individual feature; OR 15 (5.2-44), and area under the curve 0.79. However, inter-observer agreement was moderate (κ 0.53). In the second set, TIL and CLI were scored according to updated scoring systems. Although both remained the best individual discriminators, test characteristics and inter-observer agreement did not improve. MSI-H pathology features have moderate accuracy for identifying MSI-H CRC, and are identified with moderate inter-observer agreement. These findings highlight the limitations of clinical strategies, such as the revised Bethesda guidelines, which incorporate the MSI-H associated pathology features in their strategy to identify persons with lynch syndrome.

Pancreatic cancer risk in Peutz-Jeghers syndrome patients: a large cohort study and implications for surveillance.

BACKGROUND: Although Peutz-Jeghers syndrome (PJS) is known to be associated with pancreatic cancer (PC), estimates of this risk differ widely. This hampers counselling of patients and implementation of surveillance strategies. We therefore aimed to determine the PC risk in a large cohort of Dutch PJS patients. METHODS: PJS was defined by diagnostic criteria recommended by the WHO, a proven LKB1 mutation, or both. All patients with a presumptive diagnosis of pancreatic, ampullary or distal bile duct cancer were identified. Cases were reviewed clinically, radiologically and immunohistochemically. Cumulative PC risks were calculated by Kaplan-Meier analysis and relative risks by Poisson regression analysis. RESULTS: We included 144 PJS patients (49% male) from 61 families (5640 person years follow-up). Seven (5%) patients developed PC at a median age of 54 years. Four patients (3%) were diagnosed with distal bile duct (n=2) or ampullary cancer (n=2) at a median age of 55 years. The cumulative risk for PC was 26% (95% CI 4% to 47%) at age 70 years and relative risk was 76 (95% CI 36 to 160; p<0.001). The cumulative risk for pancreatico-biliary cancer was 32% (95% CI 11% to 52%) at age 70 years, with a relative risk of 96 (95% CI 53 to 174; p<0.001). CONCLUSIONS: PJS patients have a highly increased risk for pancreatico-biliary cancer. Therefore, patients are eligible for surveillance within well defined research programmes to establish the benefit of such surveillance.

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.

Yield of routine molecular analyses in colorectal cancer patients ≤70 years to detect underlying Lynch syndrome.

Although early detection of Lynch syndrome (LS) is important, a considerable proportion of patients with LS remains unrecognized. We aimed to study the yield of LS detection by routine molecular analyses in colorectal cancer (CRC) patients until 70 years of age. We prospectively included consecutive CRC patients ≤70 years. Tumour specimens were analysed for microsatellite instability (MSI), immunohistochemical mismatch-repair protein expression and MLH1-promoter methylation. Tumours were classified as either: (a) likely caused by LS; (b) sporadic microsatellite-unstable (MSI-H); or (c) microsatellite-stable (MSS). Predictors of LS were determined by multivariable logistic regression. A total of 1117 CRC patients (57% males, median age 61 years) were included. Fifty patients (4.5%, 95% CI 3.4-5.9) were likely to have LS, and 71 had a sporadic MSI-H tumour (6.4%, 95% CI 5.1-8.0). Thirty-five patients likely to have LS (70%) were aged > 50 years. A molecular profile compatible with LS was detected in 10% (15/144) of patients aged ≤50, in 4% (15/377) of those aged 51-60 and in 3% (20/596) of patients > 61 years. Compared to MSS cases, patients likely to have LS were significantly younger (OR 3.9, 95% CI 1.7-8.7) and more often had right-sided CRCs (OR 14, 95% CI 6.0-34). In conclusion, molecular screening for LS in CRC patients ≤70 years leads to identification of a molecular profile compatible with LS in 4.5% of patients, with most of them not fulfilling the age criterion (≤50 years) routinely used for LS assessment. Routine use of MSI testing may be considered in CRC patients up to the age of 70 years, with a central role for the pathologist in the selection of patients.

Peutz-Jeghers syndrome and family planning: the attitude towards prenatal diagnosis and pre-implantation genetic diagnosis.

Peutz-Jeghers syndrome (PJS) is a hereditary disorder caused by LKB1 gene mutations, and is associated with considerable morbidity and decreased life expectancy. This study was conducted to assess the attitude of PJS patients towards family planning, prenatal diagnosis (PND) and pregnancy termination, and pre-implantation genetic diagnosis (PGD). In a cross-sectional study, 61 adult PJS patients were asked to complete a questionnaire concerning genetic testing, family planning, PND and PGD. The questionnaire was completed by 52 patients (85% response rate, 44% males) with a median age of 44 (range 18-74) years. A total of 37 (71%) respondents had undergone genetic testing. In all, 24 respondents (46%, 75% males) had children. A total of 15 (29%) respondents reported that their diagnosis of PJS had influenced their decisions regarding family planning, including 10 patients (19%, 9/10 females) who did not want to have children because of their disease. Termination of pregnancy after PND in case of a foetus with PJS was considered 'acceptable' for 15% of the respondents, whereas 52% considered PGD acceptable. In conclusion, the diagnosis of PJS influences the decisions regarding family planning in one third of PJS patients, especially in women. Most patients have a negative attitude towards pregnancy termination after PND, while PGD in case of PJS is judged more acceptable. These results emphasise the importance of discussing aspects regarding family planning with PJS patients, including PND and PGD.

High cancer risk and increased mortality in patients with Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is associated with an increased cancer risk. As the determination of optimal surveillance strategies is hampered by wide ranges in cancer risk estimates and lack of data on cancer-related mortality, we assessed cancer risks and mortality in a large cohort of patients with PJS. METHODS: Dutch PJS patients were included in this cohort study. Patients were followed prospectively between January 1995 and July 2009, and clinical data from the period before 1995 were collected retrospectively. Data were obtained by interview and chart review. Cumulative cancer risks were calculated by Kaplan-Meier analysis and relative cancer and mortality risks by Poisson regression analysis. RESULTS: We included 133 PJS patients (48% males) from 54 families, contributing 5004 person-years of follow-up. 49 cancers were diagnosed in 42 patients (32%), including 25 gastrointestinal (GI) cancers. The median age at first cancer diagnosis was 45 years. The cumulative cancer risk was 20% at age 40 (GI cancer 12%), increasing to 76% at age 70 (GI cancer 51%). Cumulative cancer risks were higher for females than for males (p=0.005). The relative cancer risk was higher in PJS patients than in the general population (HR 8.96; 95% CI 6.46 to 12.42), and higher among female (HR 20.40; 95% CI 13.43 to 30.99) than among male patients (HR 4.76; 95% CI 2.82 to 8.04). 42 patients had died at a median age of 45 years, including 28 cancer-related deaths (67%). Mortality was increased in our cohort compared to the general population (HR 3.50; 95% CI 2.57 to 4.75). CONCLUSIONS: PJS patients carry high cancer risks, leading to increased mortality. The malignancies occur particularly in the GI tract and develop at young age. These results justify surveillance in order to detect malignancies in an early phase to improve outcome.

A review on the molecular diagnostics of Lynch syndrome: a central role for the pathology laboratory.

Lynch syndrome (LS) is caused by mutations in mismatch repair genes and is characterized by a high cumulative risk for the development of mainly colorectal carcinoma and endometrial carcinoma. Early detection of LS is important since surveillance can reduce morbidity and mortality. However, the diagnosis of LS is complicated by the absence of a pre-morbid phenotype and germline mutation analysis is expensive and time consuming. Therefore it is standard practice to precede germline mutation analysis by a molecular diagnostic work-up of tumours, guided by clinical and pathological criteria, to select patients for germline mutation analysis. In this review we address these molecular analyses, the central role for the pathologist in the selection of patients for germline diagnostics of LS, as well as the molecular basis of LS.

Underutilization of microsatellite instability analysis in colorectal cancer patients at high risk for Lynch syndrome.

OBJECTIVE: The revised Bethesda Guidelines were published to improve the efficiency of recognizing Lynch syndrome (LS) by identifying LS-related malignancies that should be analyzed for microsatellite instability (MSI). The aim of this study was to evaluate whether MSI analysis was performed in colorectal cancer patients at risk for LS according to the revised Bethesda Guidelines. MATERIAL AND METHODS: Patients diagnosed with colorectal cancer in 11 Dutch hospitals in 2005 and 2006 were selected from a regional database. The patients were included in the study if they met any of the following criteria; 1) diagnosed with colorectal cancer <50 years, 2) a second LS-associated tumor prior to the diagnosis of colorectal cancer in 2005/2006, and 3) colorectal cancer <60 years with a tumor displaying mucinous or signet-ring differentiation or medullary growth pattern. RESULTS: Of 1905 colorectal cancer patients, 169 met at least one of the inclusion criteria. MSI analysis had been performed in 23 (14%) of the 169 tumors. MSI status had been determined in 18 of 80 included patients aged <50 years, in 4 of 70 patients with a second LS-related tumor, and in 3 of 41 patients aged <60 years with high-risk pathology features. CONCLUSIONS: There is marked underutilization of MSI analysis in patients at risk for LS. As a result LS might be underdiagnosed both in patients with colorectal cancer and in their relatives.