Lynch Syndrome Screening Strategies Among Newly Diagnosed Endometrial Cancer Patients

An Overview of Endometrial Cancer with Novel Therapeutic Strategies

Endometrial cancer (EC) stands as the most prevalent gynecologic malignancy. In the past, it was classified based on its hormone sensitivity. However, The Cancer Genome Atlas has categorized EC into four groups, which offers a more objective and reproducible classification and has been shown to have prognostic and therapeutic implications. Hormonally driven EC arises from a precursor lesion known as endometrial hyperplasia, resulting from unopposed estrogen. EC is usually diagnosed through biopsy, followed by surgical staging unless advanced disease is expected. The typical staging consists of a hysterectomy with bilateral salpingo-oophorectomy and sentinel lymph node biopsies, with a preference placed on a minimally invasive approach. The stage of the disease is the most significant prognostic marker. However, factors such as age, histology, grade, myometrial invasion, lymphovascular space invasion, tumor size, peritoneal cytology, hormone receptor status, ploidy and markers, body mass index, and the therapy received all contribute to the prognosis. Treatment is tailored based on the stage and the risk of recurrence. Radiotherapy is primarily used in the early stages, and chemotherapy can be added if high-grade histology or advanced-stage disease is present. The risk of EC recurrence increases with advances in stage. Among the recurrences, vaginal cases exhibit the most favorable response to treatment, typically for radiotherapy. Conversely, the treatment of widespread recurrence is currently palliative and is best managed with chemotherapy or hormonal agents. Most recently, immunotherapy has emerged as a promising treatment for advanced and recurrent EC.

Landscape of germline cancer predisposition mutations testing and management in pediatrics: Implications for research and clinical care

As germline genetic testing capacities have improved over the last two decades, increasingly more people are newly diagnosed with germline cancer susceptibility mutations. In the wake of this growth, there remain limitations in both testing strategies and translation of these results into morbidity- and mortality-reducing practices, with pediatric populations remaining especially vulnerable. To face the challenges evoked by an expanding diversity of germline cancer mutations, we can draw upon a model cancer-associated genetic condition for which we have developed a breadth of expertise in managing, Trisomy 21. We can additionally apply advances in other disciplines, such as oncofertility and pharmacogenomics, to enhance care delivery. Herein, we describe the history of germline mutation testing, epidemiology of known germline cancer mutations and their associations with childhood cancer, testing limitations, and future directions for research and clinical care.

Determination of test performance of two contemporary screening tests for Lynch syndrome in endometrial cancer: A clinical trial

BACKGROUND/PURPOSE

Published data on the performance of the immunohistochemistry (IHC) test for mismatch repair (MMR) protein expression to detect Lynch syndrome (LS) index cases suggests it is highly variable; its performance in our system was unknown. Moreover, a brief family history questionnaire (bFHQ) developed by Eiriksson and colleagues in Canada demonstrated 100% sensitivity for LS case identification thus was of interest to us, but its performance outside of its original setting was unknown. Determination of the performance of these tests requires complete LS case identification in the testing population.

METHODS

Two hundred women were recruited during routine care for endometrial cancer (EC) to administer the bFHQ and perform genetic testing for the LS genes. Independently, the IHC test was performed to screen for presumptive LS cases. We determined the sensitivity, specificity, and positive and negative predictive values of the bFHQ and IHC test as well as simulating outcomes of the complete protocols.

RESULTS

Genetic testing all participants identified 8 cases of LS out of 200 (4% prevalence), the bFHQ identified 5 of 8 of these cases (62.5%, CI: 31.5%-87.6%), and the IHC test identified 6 or 7 of 8 cases (mean of 75% or 87.5%) depending on interpretation of test results. The specificities of the bFHQ and IHC test were 56.8% (CI: 49.8%-63.7%) and 79.8% (CI: 73.6%-85.1%), respectively.

CONCLUSIONS

This study is the first, to our knowledge, to test the effectiveness of the bFHQ in an EC population since its original reporting; our results are consistent with many reports of the challenges of collecting family health history. The performance of the IHC test as a screen falls within ranges reported in the literature but do not provide the confidence to drive a decision for or against continued use of this test as a LS screen.

Universal screening for Lynch syndrome in uterine cancer patients: A quality improvement initiative

OBJECTIVE

To determine the feasibility and effectiveness of a quality improvement initiative (QI) to adopt universal screening for Lynch syndrome in uterine cancer patients at an institution that previously employed age-based screening.

METHODS

Prior to the initiative, tumors of patients with uterine cancer diagnosed at age ≤ 60 years were screened for mismatch repair deficiency (MMR) and microsatellite instability (MSI). The QI process change model adopted universal testing of all uterine cancer specimens and implemented provider training, standardized documentation, and enhanced use of the electronic medical record (EMR). We compared screening rates, results of screening, follow up of abnormal results, and final diagnoses from the pre- and post-implementation periods.

RESULTS

Pre- and post-implementation screening rates for women age ≤ 60 years at the time of diagnosis were 45/78 (57.7%) and 64/68 (94.5%), respectively. The screening rate for all patients with uterine cancer increased from 73/190 (38.4%) to 172/182 (94.5%). The rate of abnormal screening results increased from 15/190 (7.9%) to 44/182 (24.0%) cases. Genetics referral rates among screen positives increased from 3/15 (20.0%) to 16/44 (36.4%). Germline diagnoses increased from 2/190 (1.1%) with two Lynch syndrome diagnoses to 4/182 (2.2%) including three Lynch syndrome diagnoses and one BRCA1 germline diagnosis. The number of patients errantly not screened decreased from at least 32 patients to 3 patients after the intervention.

CONCLUSIONS

Adherence to screening guidelines significantly improved after interventions involving provider education, optimal use of the EMR, and simplification of screening indications. These interventions are feasible at other institutions and translatable to other screening indications.

Cost-Effectiveness of the Manchester Approach to Identifying Lynch Syndrome in Women with Endometrial Cancer

Lynch syndrome (LS) is a hereditary cancer syndrome responsible for 3% of all endometrial cancer and 5% in those aged under 70 years. It is unclear whether universal testing for LS in endometrial cancer patients would be cost-effective. The Manchester approach to identifying LS in endometrial cancer patients uses immunohistochemistry (IHC) to detect mismatch repair (MMR) deficiency, incorporates testing for MLH1 promoter hypermethylation, and incorporates genetic testing for pathogenic MMR variants. We aimed to assess the cost-effectiveness of the Manchester approach on the basis of primary research data from clinical practice in Manchester. The Proportion of Endometrial Tumours Associated with Lynch Syndrome (PETALS) study informed estimates of diagnostic performances for a number of different strategies. A recent microcosting study was adapted and was used to estimate diagnostic costs. A Markov model was used to predict long-term costs and health outcomes (measured in quality-adjusted life years, QALYs) for individuals and their relatives. Bootstrapping and probabilistic sensitivity analysis were used to estimate the uncertainty in cost-effectiveness. The Manchester approach dominated other reflex testing strategies when considering diagnostic costs and Lynch syndrome cases identified. When considering long-term costs and QALYs the Manchester approach was the optimal strategy, costing £5459 per QALY gained (compared to thresholds of £20,000 to £30,000 per QALY commonly used in the National Health Service (NHS)). Cost-effectiveness is not an argument for restricting testing to younger patients or those with a strong family history. Universal testing for Lynch syndrome in endometrial cancer patients is expected to be cost-effective in the U.K. (NHS), and the Manchester approach is expected to be the optimal testing strategy.

Comparison of two Lynch screening strategies in endometrial cancer in a California health system

OBJECTIVE

Compare detection of Lynch syndrome in endometrial cancer between regions of a health care system with different screening strategies.

METHODS

A retrospective study of endometrial cancer (EC) cases from 2 regions of an integrated health care system (Kaiser Permanente Northern (KPNC) and Southern (KPSC) California). Within KPNC, immunohistochemistry tumor screening (IHC) was physician ordered and risk-based; within KPSC, IHC was universal and automated. Clinical risk factors associated with abnormal IHC and Lynch Syndrome (LS) were identified.

RESULTS

During the study, there were 2045 endometrial cancers: 1399 in the physician-order group and 646 in the universal testing group. In the physician-order group: among women < age 60, 34% underwent IHC; 9.6% were abnormal, and 3% were possible LS after methylation testing; among women ≥60, 11% underwent IHC, 3% were abnormal and <1% were possible LS. In the universal group, 87% of women age <60 had IHC, 19.4% were abnormal, and 6% were possible LS; Among women age ≥60, 82% underwent IHC, 26% were abnormal, and 2% were possible LS. There were no differences in LS cases between the physician-order group and the universal group in either age strata (<60: 3% vs. 3.6%, p=0.62; ≥60: <1% vs. 1%, p=0.63) Factors associated with LS were younger age (odds ratio (OR) 0.11, 95% confidence interval (CI) 0.04-0.29) and lower body mass index (BMI), (OR 0.38 95% CI 0.18-0.80).

CONCLUSIONS

Universal IHC screening did not result in increased LS detection in EC.

Cost-effectiveness analysis of reflex testing for Lynch syndrome in women with endometrial cancer in the UK setting

Background

Lynch syndrome is a hereditary cancer syndrome caused by constitutional pathogenic variants in the DNA mismatch repair (MMR) system, leading to increased risk of colorectal, endometrial and other cancers. The study aimed to identify the incremental costs and consequences of strategies to identify Lynch syndrome in women with endometrial cancer.

Methods

A decision-analytic model was developed to evaluate the relative cost-effectiveness of reflex testing strategies for identifying Lynch syndrome in women with endometrial cancer taking the NHS perspective and a lifetime horizon. Model input parameters were sourced from various published sources. Consequences were measured using quality-adjusted life years (QALYs). A cost-effectiveness threshold of £20 000/QALY was used.

Results

Reflex testing for Lynch syndrome using MMR immunohistochemistry and MLH1 methylation testing was cost-effective versus no testing, costing £14 200 per QALY gained. There was uncertainty due to parameter imprecision, with an estimated 42% chance this strategy is not cost-effective compared with no testing. Age had a significant impact on cost-effectiveness, with testing not predicted to be cost-effective in patients aged 65 years and over.

Conclusions

Testing for Lynch syndrome in younger women with endometrial cancer using MMR immunohistochemistry and MLH1 methylation testing may be cost-effective. Age cut-offs may be controversial and adversely affect implementation.

Comparison of screening strategies for Lynch syndrome in patients with newly diagnosed endometrial cancer: a prospective cohort study in China

Background

The prevalence of Lynch syndrome and screening strategies for this disorder in Chinese patients with endometrial cancer have seldom been investigated. Such data would be essential for the screening, prevention, genetic counseling, and treatment of Lynch syndrome. The purpose of this prospective study was to determine the accuracy of the mismatch repair (MMR) protein immunohistochemistry (IHC), microsatellite instability (MSI) test, and clinical diagnostic criteria in screening for Lynch syndrome-associated endometrial cancer (LS-EC) in a prospective Chinese cohort.

Methods

All patients with newly diagnosed endometrial cancer (EC) were evaluated using clinical diagnostic criteria (Amsterdam II criteria and the revised Bethesda guidelines), MSI test, and IHC of MMR proteins in tumor tissues. For all patients, the screening results were compared with results of germline sequencing for pathogenic variants of MMR genes.

Results

Between December 2017 and August 2018, a total of 111 unselected patients with newly diagnosed EC were enrolled. Six patients (5.4%) harbored a pathogenic germline mutation of MMR genes: 1 had a mutation in MutL homolog 1 (MLH1), 2 in MutS homolog 2 (MSH2), and 3 in MutS homolog 6 (MSH6). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for identifying LS-EC were 33.3%, 88.6%, 14.3%, and 95.9%, for the clinical criteria, 66.7%, 75.0%, 14.3%, and 97.3% for IHC of MMR proteins, 100%, 89.9%, 33.3%, and 100% for MSI test, and 100%, 72.4%, 20.0% and 100% for combined IHC and MSI test, respectively. The combination of IHC and MSI test had higher sensitivity and PPV than the clinical criteria (p = 0.030). MSI test and IHC were highly concordant for LS-EC screening (73/77, 94.8%).

Conclusion

The accuracy of the combination of IHC of MMR proteins and MSI test for screening LS among Chinese patients with EC was superior to that of the clinical criteria.

Trial registration NCT03291106. Registered on September 25, 2017

Is immunohistochemistry-based screening for Lynch syndrome in endometrial cancer effective? The consent's the thing

PURPOSE

To investigate the plausible failure rate of the immunohistochemistry (IHC)-based screening protocol to identify Lynch syndrome (LS) index cases among endometrial cancer (EC) patients.

METHODS

We developed a simulation model of the IHC protocol in this context. The model was populated from systematic and focused reviews, augmented with local data and expert opinion. The virtual cohort represents the number of women expected to be diagnosed with EC in the U.S. in 2018. The outcomes include protocol failure rates and LS cases missed in a variety of hypothetical scenarios.

RESULTS

The best estimate of failure rate of the IHC protocol is 58%; minimum and maximum estimates are 33% and 80%, respectively. These failure rates are driven primarily by the high rates of failure to obtain consent from patients for sequencing (25% to 80%). The multiple imperfect tests and potential failure points in this protocol, collectively, make up 7% to 20% of the total failure rate. When consent for sequencing was fixed in the model at 25%, 50%, and 80%; the expected ranges for index case identification failure are 78%-82%, 57%-64%, and 29%-42%, respectively.

CONCLUSION

The primary driver of failure to identify index cases remains consent for sequencing. Consent rates have shown little improvement since LS screening programs were instituted in the U.S., leaving us to conclude these high failure rates are resistant to substantial improvement. These missed opportunities will be magnified because cascade screening for carrier status among family members will not be pursued.

A Micro-Costing Study of Screening for Lynch Syndrome-Associated Pathogenic Variants in an Unselected Endometrial Cancer Population: Cheap as NGS Chips?

Background: Lynch syndrome is the most common inherited cause of endometrial cancer. Identifying individuals affected by Lynch syndrome enables risk-reducing interventions including colorectal surveillance, and cascade testing of relatives.

Methods: We conducted a micro-costing study of screening all women with endometrial cancer for Lynch syndrome using one of four diagnostic strategies combining tumor microsatellite instability testing (MSI), immunohistochemistry (IHC), and/or MLH1 methylation testing, and germline next generation sequencing (NGS). Resource use (consumables, capital equipment, and staff) was identified through direct observation and laboratory protocols. Published sources were used to identify unit costs to calculate a per-patient cost (£; 2017) of each testing strategy, assuming a National Health Service (NHS) perspective.

Results: Tumor triage with MSI and reflex MLH1 methylation testing followed by germline NGS of women with likely Lynch syndrome was the cheapest strategy at £42.01 per case. Tumor triage with IHC and reflex MLH1 methylation testing of MLH1 protein-deficient cancers followed by NGS of women with likely Lynch syndrome cost £45.68. Tumor triage with MSI followed by NGS of all women found to have tumor microsatellite instability cost £78.95. Immediate germline NGS of all women with endometrial cancer cost £176.24. The cost of NGS was affected by the skills and time needed to interpret results (£44.55/patient).

Conclusion: This study identified the cost of reflex screening all women with endometrial cancer for Lynch syndrome, which can be used in a model-based cost-effectiveness analysis to understand the added value of introducing reflex screening into clinical practice.

Clinicopathologic features of endometrial cancer in Chinese patients younger than 50 years with a family history of cancer

Genetic factors play an important role in shaping the biologic characteristics of malignant tumors, especially in young patients. We aimed to determine the clinicopathologic features of endometrial cancer (EC) in patients younger than 50 years with a family history of cancer.Overall, 229 patients with EC, including 40 with a positive family history of cancer (PFH) and 189 with a negative family history of cancer (NFH), were enrolled in this case-control study. The family history of cancer in a 2-generation pedigree was recorded for the PFH group. Clinicopathologic features such as menarche age, body mass index, personal cancer history, grade, and histologic type were compared between the 2 groups. Mismatch repair (MMR) proteins including MLH1, PMS2, MSH2, and MSH6 were assessed by immunohistochemistry (IHC) in surgical samples. Univariate (Pearson Chi-squared test, Fisher exact test, T test, Wilcoxon rank sum test, logistic regression) statistics and stepwise multivariate logistic regression were used to identify factors associated with PFH in the analysis.Among young patients with EC, the PFH group had younger age-of-onset age of endometrial cancer (≤40 years) (odds ratio [OR] = 2.21, 95% confidence interval [95% CI]: 1.01-4.82) than the NFH group. The proportion of overweight/obese patients was high in both the NFH (58.7%) and PFH (80%) groups. Colorectal, lung, endometrial, breast, and hepatocellular carcinoma accounted for 58.6% of all cancer types among 1st- and 2nd-degree relatives. Additionally, 19.2% of patients displayed deficiency in at least 1 MMR protein, with a significantly higher proportion of MMR protein deficiency in the PFH group than in the NFH group (adjusted OR = 4.81, 95% CI: 2.14-8.83).Clinicopathologic features differ for young patients with EC with and without a family history of cancer. Surveillance of age-of-onset and family history of endometrial cancer, reduction of barriers to healthy lifestyles, and development of risk-appropriate Lynch syndrome screening tools, such as IHC, are needed for these women in Shanghai and other developing cities in China.

The practice of universal screening for Lynch syndrome in newly diagnosed endometrial carcinoma

BACKGROUND

Lynch syndrome (LS) accounts for 5% of all endometrial cancer (EC) cases and 4% of all lifetime risk of developing colorectal cancer. While current guidelines recommend LS screening for all patients with newly diagnosed colorectal cancer, there is no such guideline for screening patients with EC.

DISCUSSION

This review addresses LS screening and discusses algorithms for testing patients in the setting of newly diagnosed EC.

CONCLUSION

The successful diagnosis of LS has important implications, including prevention of LS-associated cancers among relatives and immunotherapy recommendations for patients with advanced EC and loss of expression of mismatch repair immunohistochemistry and microsatellite instability positive following failure of traditional treatment.

Identifying Lynch Syndrome in Women Presenting With Endometrial Carcinoma Under the Age of 50 Years

BACKGROUND

Lynch syndrome (LS) is an inherited disorder associated with genetic predisposition to endometrial, colorectal, ovarian, and other cancers. There is consensus for the necessity of assessment for LS in view of the established survival benefits for identified patients and affected family members. The debate regarding the best screening policy is far from being concluded.

OBJECTIVES

The aim of this study was to evaluate a realistic protocol for identifying LS families by assessing young women with a diagnosis of endometrial cancer (EC).

METHODS

Consecutive cases of women with a diagnosis of endometrioid EC younger than 50 years were recruited. A complete 3-generation pedigree was drawn and assessed against the Amsterdam II criteria. Tumor DNA microsatellite instability and immunohistochemistry testing for the expression of mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2 was offered to all patients. MLH1 gene promoter methylation and EPCAM gene deletion testing were also offered where appropriate. Genetic counseling and MMR germline mutation tests were offered in women with abnormal results.

RESULTS

Fifty-eight women were invited, and 38 (65.5%), consented for LS assessment (95% confidence interval CI 53%-78%). A complete data set was obtained in 35 women (60.3%). Lynch syndrome according to clinical and/or molecular characteristics was diagnosed in 8 cases or 22.8% (95% CI 15%-48%). There was no significant difference at the age of women with a diagnosis of LS (median, 45 years; range, 37-48 years) compared with that of the non-LS ones (median, 45 years; range, 31-49 years). Three pathogenic MMR mutations were identified in the 8 cases with a diagnosis of LS, 37.5% (95% CI 5%-72%), estimating an 8.5% (95% CI 1%-19%) mutation prevalence in the study population.

CONCLUSIONS

All women with newly diagnosed EC should be assessed for inherited predisposition. Regional policies for assessment should be developed in accordance with available resources. Gynecologists are required to upgrade their skills in order to identify, assess, and counsel patients with suspected or established LS and appropriately refer to clinical genetics.

Importance of PCR-based Tumor Testing in the Evaluation of Lynch Syndrome-associated Endometrial Cancer

Lynch syndrome (LS) is a hereditary cancer syndrome caused by a germline mutation in a DNA mismatch repair gene, usually MLH1, MSH2, MSH6, or PMS2. The most common cancers associated with LS are colorectal adenocarcinoma and endometrial carcinoma. Identification of women with LS-associated endometrial cancer is important, as these women and their affected siblings and children are at-risk of developing these same cancers. Germline testing of all endometrial cancer patients is not cost effective, and screening using young age of cancer diagnosis and/or presence of family history of syndrome-associated is underutilized and ineffective. Therefore, most groups now advocate for tumor tissue testing to screen for LS, with germline testing targeted to women with abnormal tissue testing results. Immunohistochemistry for MLH1, MSH2, MSH6, and PMS2 is used in many clinical laboratories for this tumor screening step, as immunohistochemistry is relatively inexpensive and is technically more accessible for smaller clinical labs. PCR-based tissue testing, whereas technically more challenging, does play an important role in the identification of these patients. MLH1 methylation analysis identifies women with tumor MLH1 loss who likely have sporadic endometrial cancer and do not need heightened cancer prevention surveillance. High levels of microsatellite instability have been identified in tumors with retained positive expression of mismatch repair proteins. Somatic sequencing of mismatch repair genes from tumor DNA, whereas not currently available in most clinical laboratories, is helpful in resolution of cases in which germline sequencing fails to identify a mutation in a mismatch repair gene. The tumor tissue testing approach can help to identify most women at-risk for germline mutations in a LS gene, but not all patients will be captured using this approach. Clinical suspicion can still play a pivotal role in accurately identifying a subset of these patients.

Hereditary Colorectal Polyposis and Cancer Syndromes: A Primer on Diagnosis and Management

Colorectal cancer (CRC) is the fourth most common cancer amongst men and women. Between 3 and 6% of all CRCs are attributed to well-defined inherited syndromes, including Lynch syndrome, familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), and several hamartomatous polyposis conditions. Identification of these patients through family history and appropriate genetic testing can provide estimates of cancer risk that inform appropriate cancer screening, surveillance and/or preventative interventions. This narrative review examines the hereditary colorectal cancer and polyposis syndromes, their genetic basis, clinical management, and evidence supporting cancer screening.

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

PURPOSE

To assess cost-effectiveness of routine screening for Lynch Syndrome (LS) in endometrial cancer (EC) patients ≤70years of age.

METHODS

Consecutive EC patients ≤70years of age were screened for LS by analysis of microsatellite instability, immunohistochemistry and MLH1 hypermethylation. Costs and health benefit in life years gained (LYG) included surveillance for LS carriers among EC patients and relatives. We calculated incremental cost-effectiveness ratios (ICERs) comparing LS screening among EC patients ≤70years with ≤50years and the revised Bethesda guidelines.

RESULTS

Screening for LS in 179 EC patients identified 7 LS carriers; 1 was ≤50 and 6 were 51-70years. Per age category 18 and 9 relatives were identified as LS carrier. Screening resulted in 74,7 LYG (45,4 and 29,3 LYG per age category). The ICER for LS screening in EC patients ≤70 compared with ≤50years was €5,252/LYG. The revised Bethesda guidelines missed 4/7 (57%) LS carriers among EC patients. The ICER for LS screening in EC patients ≤70years of age compared with the revised Bethesda guidelines was €6,668/LYG. Both ICERs remained <€16,000/LYG in sensitivity analyses.

CONCLUSION

Routine LS screening in EC patients ≤70years is a cost-effective strategy, allowing colorectal cancer prevention in EC patients and their relatives.

Lynch Syndrome: Female Genital Tract Cancer Diagnosis and Screening

Lynch syndrome is responsible for approximately 5% of endometrial cancers and 1% of ovarian cancers. The molecular basis for Lynch syndrome is a heritable functional deficiency in the DNA mismatch repair system, typically due to a germline mutation. This review discusses the rationales and relative merits of current Lynch syndrome screening tests for endometrial and ovarian cancers and provides pathologists with an informed algorithmic approach to Lynch syndrome testing in gynecologic cancers. Pitfalls in test interpretation and strategies to resolve discordant test results are presented. The potential role for next-generation sequencing panels in future screening efforts is discussed.

Practical issues related to uterine pathology: staging, frozen section, artifacts, and Lynch syndrome

This review covers three areas in endometrial tumor pathology: International Federation of Gynecology and Obstetrics (FIGO) staging, the use of frozen section, and Lynch syndrome. The section on FIGO staging will emphasize problems that practicing pathologists often confront, such as measuring the depth of myometrial invasion, assessing for the presence of cervical stromal invasion, detecting low-volume lymph node metastases, and recognizing synchronous endometrial and ovarian tumors and artifacts. The frozen section portion of this review will focus on the performance characteristics of intraoperative examination of the uterus to determine tumor grade and depth of myometrial invasion, including suggestions for alternative methods. The last portion of this review will provide an overview of Lynch syndrome and a discussion of the rationale and methods of screening for Lynch syndrome.

Screening for Lynch syndrome among patients with newly diagnosed endometrial cancer: a comprehensive review

Lynch syndrome (LS) is an autosomal dominant condition characterized by an increased risk of hereditary colorectal, endometrial, ovarian, pancreatic, urinary tract, and gastric cancer.It is estimated that around 5% of all endometrial cancer (EC) cases are due to an inherited predisposition, of which LS might be the most frequent. The lifetime risk of developing EC in women with LS ranges between 40% and 71% depending on the type of mutation. In many cases, this risk may even exceed their risk of developing colon cancer. Moreover, in 60% of these women, EC will be the first primary malignancy diagnosed and the sentinel diagnosis of the syndrome. Therefore, it is essential to identify which women with EC have LS in order to allow implementation of individualized screening and preventive strategies.

A systematic review and economic evaluation of diagnostic strategies for Lynch syndrome

BACKGROUND

Lynch syndrome (LS) is an inherited autosomal dominant disorder characterised by an increased risk of colorectal cancer (CRC) and other cancers, and caused by mutations in the deoxyribonucleic acid (DNA) mismatch repair genes.

OBJECTIVE

To evaluate the accuracy and cost-effectiveness of strategies to identify LS in newly diagnosed early-onset CRC patients (aged < 50 years). Cascade testing of relatives is employed in all strategies for individuals in whom LS is identified.

DATA SOURCES AND METHODS

Systematic reviews were conducted of the test accuracy of microsatellite instability (MSI) testing or immunohistochemistry (IHC) in individuals with CRC at risk of LS, and of economic evidence relating to diagnostic strategies for LS. Reviews were carried out in April 2012 (test accuracy); and in February 2012, repeated in February 2013 (economic evaluations). Databases searched included MEDLINE (1946 to April week 3, 2012), EMBASE (1980 to week 17, 2012) and Web of Science (inception to 30 April 2012), and risk of bias for test accuracy was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) quality appraisal tool. A de novo economic model of diagnostic strategies for LS was developed.

RESULTS

Inconsistencies in study designs precluded pooling of diagnostic test accuracy results from a previous systematic review and nine subsequent primary studies. These were of mixed quality, with significant methodological concerns identified for most. IHC and MSI can both play a part in diagnosing LS but neither is gold standard. No UK studies evaluated the cost-effectiveness of diagnosing and managing LS, although studies from other countries generally found some strategies to be cost-effective compared with no testing. The de novo model demonstrated that all strategies were cost-effective compared with no testing at a threshold of £20,000 per quality-adjusted life-year (QALY), with the most cost-effective strategy utilising MSI and BRAF testing [incremental cost-effectiveness ratio (ICER) = £5491 per QALY]. The maximum health benefit to the population of interest would be obtained using universal germline testing, but this would not be a cost-effective use of NHS resources compared with the next best strategy. When the age limit was raised from 50 to 60 and 70 years, the ICERs compared with no testing increased but remained below £20,000 per QALY (except for universal germline testing with an age limit of 70 years). The total net health benefit increased with the age limit as more individuals with LS were identified. Uncertainty was evaluated through univariate sensitivity analyses, which suggested that the parameters substantially affecting cost-effectiveness: were the risk of CRC for individuals with LS; the average number of relatives identified per index patient; the effectiveness of colonoscopy in preventing metachronous CRC; the cost of colonoscopy; the duration of the psychological impact of genetic testing on health-related quality of life (HRQoL); and the impact of prophylactic hysterectomy and bilateral salpingo-oophorectomy on HRQoL (this had the potential to make all testing strategies more expensive and less effective than no testing).

LIMITATIONS

The absence of high-quality data for the impact of prophylactic gynaecological surgery and the psychological impact of genetic testing on HRQoL is an acknowledged limitation.

CONCLUSIONS

Results suggest that reflex testing for LS in newly diagnosed CRC patients aged < 50 years is cost-effective. Such testing may also be cost-effective in newly diagnosed CRC patients aged < 60 or < 70 years. Results are subject to uncertainty due to a number of parameters, for some of which good estimates were not identified. We recommend future research to estimate the cost-effectiveness of testing for LS in individuals with newly diagnosed endometrial or ovarian cancer, and the inclusion of aspirin chemoprevention. Further research is required to accurately estimate the impact of interventions on HRQoL.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002436.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Hereditary Syndromes Manifesting as Endometrial Carcinoma: How Can Pathological Features Aid Risk Assessment?

Endometrial carcinoma is the most common gynecological tumor worldwide. It can be the presenting malignancy, acting as the harbinger, of an undiagnosed hereditary syndrome. Up to 50% of females with Lynch syndrome present in this manner. Differentiation between Lynch, Muir-Torre, and Cowden syndromes can at times be challenging due to the overlapping features. Our review emphasizes on the strengths, pitfalls, and limitations of microscopic features as well as immunohistochemical and polymerase chain reaction- (PCR-) based tests used by laboratories to screen for DNA mismatch repair (MMR) and PTEN gene mutations in patients to enable a more targeted and cost effective approach in the use of confirmatory gene mutational analysis tests. This is crucial towards initiating timely and appropriate surveillance measures for the patient and affected family members. We also review the evidence postulating on the possible inclusion of uterine serous carcinoma as part of the spectrum of malignancies seen in hereditary breast and ovarian carcinoma syndrome, driven by mutations in BRCA1/2.

Economic evidence on identifying clinically actionable findings with whole-genome sequencing: a scoping review

The American College of Medical Genetics and Genomics (ACMG) recommends that mutations in 56 genes for 24 conditions are clinically actionable and should be reported as secondary findings after whole-genome sequencing (WGS). Our aim was to identify published economic evaluations of detecting mutations in these genes among the general population or among targeted/high-risk populations and conditions and identify gaps in knowledge. A targeted PubMed search from 1994 through November 2014 was performed, and we included original, English-language articles reporting cost-effectiveness or a cost-to-utility ratio or net benefits/benefit-cost focused on screening (not treatment) for conditions and genes listed by the ACMG. Articles were screened, classified as targeting a high-risk or general population, and abstracted by two reviewers. General population studies were evaluated for actual cost-effectiveness measures (e.g., incremental cost-effectiveness ratios (ICER)), whereas studies of targeted populations were evaluated for whether at least one scenario proposed was cost-effective (e.g., ICER of ≤$100,000 per life-year or quality-adjusted life-year gained). A total of 607 studies were identified, and 32 relevant studies were included. Identified studies addressed fewer than one-third (7 of 24; 29%) of the ACMG conditions. The cost-effectiveness of screening in the general population was examined for only 2 of 24 conditions (8%). The cost-effectiveness of most genetic findings that the ACMG recommends for return has not been evaluated in economic studies or in the context of screening in the general population. The individual studies do not directly address the cost-effectiveness of WGS.

Reflex testing for Lynch syndrome: if we build it, will they come? Lessons learned from the uptake of clinical genetics services by individuals with newly diagnosed colorectal cancer (CRC)

The aim of this qualitative study was to examine the experience of individuals facing a choice about genetic counselling/testing in the context of newly diagnosed colorectal cancer (CRC). Nineteen individuals with newly diagnosed CRC, including 12 individuals who accepted genetic counselling (“acceptors”) and 7 individuals who declined genetic counselling (“refusers”), were interviewed using a standardized questionnaire guide which focused on motivations and barriers experienced in the decision process. Data were analyzed using Karlsson’s Empirical Phenomenological method of data analysis (Karlsson in Psychological qualitative research from a phenomenological perspective. Almgvist and Wiksell International, Stockholm, 1993). Three major themes were identified: facing challenges in health literacy; mapping an unknown territory; and adjusting to cancer. The study participants’ testimonies provided novel insights into potential reasons for patient non-engagement in pilot studies of reflex testing for Lynch syndrome, and allowed us to formulate several recommendations for enhancing patient engagement. Our study findings suggest that patient engagement in clinical cancer genetics services, including reflex testing for Lynch syndrome, can only be achieved by addressing current health literacy issues, by deconstructing current misconceptions related to potential abuses of genetic information, by emphasizing the clinical utility of genetic assessment, and by adapting genetics practices to the specific context of cancer care.

Hereditary and common familial colorectal cancer: evidence for colorectal screening

Colorectal cancer (CRC) is the fourth most common cancer among men and women. Between 3 and 6% of all CRCs are attributed to well-defined inherited syndromes, including Lynch syndrome, familial adenomatous polyposis, MUTYH-associated polyposis and several hamartomatous conditions. Up to 30% of CRC cases exhibit common familial risk, likely related to a combination of inherited factors and environment. Identification of these patients through family history and appropriate genetic testing can provide estimates of cancer risk that inform appropriate cancer screening, surveillance and/or preventative interventions. This article examines the colon cancer syndromes, their genetic basis, clinical management and evidence supporting colorectal screening. It also deals with the category of common (non-syndromic) familial risk including risk determination and screening guidelines.

Impact of an immunohistochemistry-based universal screening protocol for Lynch syndrome in endometrial cancer on genetic counseling and testing

OBJECTIVE

Evaluate effects of a Lynch syndrome universal screening protocol in newly diagnosed endometrial cancers on subsequent genetic counseling (GC) and germline testing (GT) referral and acceptance rates.

METHODS

We performed a retrospective cohort study of women who underwent a hysterectomy for endometrial cancer at Barnes Jewish Hospital in St. Louis, MO between 1/1/2011 and 12/31/2013 (n=637). An immunohistochemistry-based (IHC) universal screening protocol for Lynch syndrome was initiated on 12/17/2012. The cohorts consisted of women presenting prior to (Pre-Em-USP; n=395) and those presenting following (Em-USP; n=242) initiation of the universal screening protocol. GC and GT referrals were based on risk factors and/or IHC results. Comparisons were made using the Fisher's exact test and the Kruskal-Wallis test.

RESULTS

A greater proportion of individuals in the Em-USP cohort underwent GT than in Pre-Em-USP (9.1% vs 4.8%, p<0.05). Of individuals with an IHC screening result suggestive of LS, those within the Em-USP cohort were significantly more likely to accept GC compared to those in the Pre-Em-USP cohort (95% vs 64%, p=0.02). Specifically within the Em-USP cohort, patients referred to GC due to a concerning IHC screening result, versus those who were referred based on other risk factors, had a higher counseling acceptance rate (95% vs 61%, p=0.03) and underwent genetic testing more readily (76% vs 30%, p<0.001).

CONCLUSIONS

Implementation of an IHC-based universal screening protocol for LS in endometrial cancer leads to higher acceptance of genetic counseling and higher rates of genetic testing compared to referral based on risk factors alone.

Lynch syndrome screening should be considered for all patients with newly diagnosed endometrial cancer

Lynch syndrome (LS) is an autosomal dominant inherited disorder caused by germline mutations in DNA mismatch repair (MMR) genes. Mutation carriers are at substantially increased risk of developing cancers of the colorectum and endometrium, among others. Given recent recommendations for universal, cost-effective screening of all patients with newly diagnosed colorectal cancer using MMR protein immunohistochemistry, we evaluated MMR protein expression in a series of endometrial cancers in the general population. A total of 605 consecutive cases of primary endometrial cancer at a single institution (1997 to 2013) were evaluated regardless of age, family history, or histologic features. Evaluation methods consisted of immunohistochemistry for the MMR proteins MLH1, MSH2, MSH6, and PMS2, followed by DNA methylation analysis for cases with MLH1/PMS2 deficiency. Germline mutation testing was performed on a subset of cases. Forty MMR-deficient, nonmethylated endometrial cancers were identified: 3 MLH1/PMS2 and 37 MSH6/MSH2 protein deficiencies. Only 25% occurred in women below 50 years of age (range, 39 to 88 y), 1 of which was in a risk-reducing hysterectomy specimen. Only 15% of patients had a prior history of carcinoma, including only 2 patients with prior colorectal carcinoma. Most (80%) of the endometrial cancers were purely endometrioid; there were 2 mixed endometrioid/mucinous, 1 mucinous, 1 serous, 2 clear cell, and 2 carcinosarcoma cases. When grading was applicable, 40% of the endometrial malignancies were FIGO grade 1, 34% grade 2, and 26% grade 3. Thirteen percent arose in the lower uterine segment, and 23% had tumor-infiltrating lymphocytes. Of the tumors with known germline testing, 41% with a LS-associated germline mutation were not associated with any of the traditional indicators that have been recommended for LS screening (ie, age 50 y or younger, personal/family cancer pedigree that meets Bethesda guideline criteria, presence of MMR-associated tumor morphology, or location in the lower uterine segment). These data suggest that a significant number of LS-associated endometrial carcinomas are missed using clinical, histologic, and locational screening parameters and provide support for universal screening of all newly diagnosed endometrial cancers.

Utility of MLH1 methylation analysis in the clinical evaluation of Lynch Syndrome in women with endometrial cancer

Clinical screening criteria, such as young age of endometrial cancer diagnosis and family history of signature cancers, have traditionally been used to identify women with Lynch Syndrome, which is caused by mutation of a DNA mismatch repair gene. Immunohistochemistry and microsatellite instability analysis have evolved as important screening tools to evaluate endometrial cancer patients for Lynch Syndrome. A complicating factor is that 15-20% of sporadic endometrial cancers have immunohistochemical loss of the DNA mismatch repair protein MLH1 and high levels of microsatellite instability due to methylation of MLH1. The PCR-based MLH1 methylation assay potentially resolves this issue, yet many clinical laboratories do not perform this assay. The objective of this study was to determine if clinical and pathologic features help to distinguish sporadic endometrial carcinomas with MLH1 loss secondary to MLH1 methylation from Lynch Syndrome-associated endometrial carcinomas with MLH1 loss and absence of MLH1 methylation. Of 337 endometrial carcinomas examined, 54 had immunohistochemical loss of MLH1. 40/54 had MLH1 methylation and were designated as sporadic, while 14/54 lacked MLH1 methylation and were designated as Lynch Syndrome. Diabetes and deep myometrial invasion were associated with Lynch Syndrome; no other clinical or pathological variable distinguished the 2 groups. Combining Society of Gynecologic Oncology screening criteria with these 2 features accurately captured all Lynch Syndrome cases, but with low specificity. In summary, no single clinical/pathologic feature or screening criteria tool accurately identified all Lynch Syndrome-associated endometrial carcinomas, highlighting the importance of the MLH1 methylation assay in the clinical evaluation of these patients.

Risk of secondary malignancy (including breast) in patients with mismatch-repair protein deficiency

Lynch syndrome (LS) is an autosomal dominant inherited disease that is associated with an increased risk for colorectal and endometrial cancer due to germline mutations in mismatch-repair (MMR) genes. Whereas primary tumors in this syndrome are widely recognized, the relative risk(s) of secondary malignancies, particularly breast cancer, in LS patients are still poorly characterized. To provide an improved assessment of these risks, MMR status was evaluated in secondary tumors from a series of patients with index tumors of known MMR status (both proficient and deficient). A total of 1252 tumors (index tumors) and all secondary malignancies were tested for MMR by immunohistochemistry (MSH2, MSH6, MLH1, PMS2) between 1992 and 2013. Tumors with MLH1/PMS2 deficiency were tested for hypermethylation or BRAF mutation, when appropriate. Of the 1252 index tumors, 162 were MMR deficient (dMMR), and, of that subset, 32 secondary tumors were identified (19.7%). In contrast, 80 secondary tumors were identified in the proficient (intact) group (7.3%). Although secondary malignancies were more common in the dMMR group (P=0.0001), there was no trend in tumor type. Specifically, breast cancer was not overly represented in the dMMR group. When secondary tumors had dMMR, they were more likely to have deficiency in MSH2/MSH6 than in MLH1/PMS2 (P=0.01). Of the patients with tumors exhibiting dMMR, women were more likely to have a dMMR secondary tumor in this series (P=0.0001); however, breast cancer was not overly represented, and our study provides no evidence that it is more frequent in LS. MSH2/MSH6 deficiency is more commonly associated with a secondary tumor compared with MLH1/PMS2 deficiency, when methylation/BRAF status is taken into account.

Role of the clinical pathology laboratory in the evaluation of endometrial carcinomas for Lynch syndrome

Molecular diagnostic testing of endometrial carcinomas in the pathology laboratory has recently emerged as a key component of the clinical evaluation of Lynch syndrome in many centers. Testing modalities involve immunohistochemical and PCR-based analyses. This article outlines the routine application of these analyses, provides a practical guide for troubleshooting some of the common technical issues related to their performance, and reviews common pitfalls in their interpretation. Discrepancies between tissue testing and genetic testing results are discussed in the context of the current understanding of endometrial cancer biology. The merits of universal versus targeted tissue testing based on clinical patient history and histological tumor appearance are also addressed.

Prevalence of Lynch syndrome among patients with newly diagnosed endometrial cancers

BACKGROUND

Lynch syndrome (LS) is a hereditary condition that increases the risk for endometrial and other cancers. The identification of endometrial cancer (EC) patients with LS has the potential to influence life-saving interventions. We aimed to study the prevalence of LS among EC patients in our population.

METHODS

Universal screening for LS was applied for a consecutive series EC. Tumor testing using microsatellite instability (MSI), immunohistochemistry (IHC) for mismatch-repair (MMR) protein expression and MLH1-methylation analysis, when required, was used to select LS-suspicious cases. Sequencing of corresponding MMR genes was performed.

RESULTS

One hundred and seventy-three EC (average age, 63 years) were screened. Sixty-one patients (35%) had abnormal IHC or MSI results. After MLH1 methylation analysis, 27 cases were considered suspicious of LS. From these, 22 were contacted and referred for genetic counseling. Nineteen pursued genetic testing and eight were diagnosed of LS. Mutations were more frequent in younger patients (<50 yrs). Three cases had either intact IHC or MSS and reinforce the need of implement the EC screening with both techniques.

CONCLUSION

The prevalence of LS among EC patients was 4.6% (8/173); with a predictive frequency of 6.6% in the Spanish population. Universal screening of EC for LS is recommended.

Relationship between PTEN, DNA mismatch repair, and tumor histotype in endometrial carcinoma: retained positive expression of PTEN preferentially identifies sporadic non-endometrioid carcinomas

Loss of PTEN (phosphatase and tensin homolog) expression and microsatellite instability are two of the more common molecular alterations in endometrial carcinoma. From the published literature, it is controversial as to whether there is a relationship between these different molecular mechanisms. Therefore, a cohort of 187 pure endometrioid and non-endometrioid endometrial carcinomas, carefully characterized as to clinical and pathological features, was examined for PTEN sequence abnormalities and the immunohistochemical expression of PTEN and the DNA mismatch repair proteins MLH1, MSH2, MSH6, and PMS2. MLH1 methylation analysis was performed when tumors had loss of MLH1 protein. Mismatch repair protein loss was more frequent in endometrioid carcinomas compared with non-endometrioid carcinomas, a difference primarily attributable to the presence of MLH1 methylation in a greater proportion of endometrioid tumors. Among the non-endometrioid group, mixed endometrioid/non-endometrioid carcinomas were the histotype that most commonly had loss of a mismatch repair protein. In endometrioid tumors, the frequency of PTEN loss measured by immunohistochemistry and mutation did not differ significantly between the mismatch repair protein intact or mismatch repair protein loss groups, suggesting that PTEN loss is independent of mismatch protein repair status in this group. However, in non-endometrioid carcinomas, both intact positive PTEN immunohistochemical expression and PTEN wild type were highly associated with retained positive expression of mismatch repair proteins in the tumor. Relevant to screening endometrial cancers for Lynch Syndrome, an initial PTEN immunohistochemistry determination may be able to replace the use of four mismatch repair immunohistochemical markers in 63% of patients with non-endometrioid endometrial carcinoma. Therefore, PTEN immunohistochemistry, in combination with tumor histotype, is a useful adjunct in the clinical evaluation of endometrial carcinomas for Lynch Syndrome.

Genetic testing strategies in newly diagnosed endometrial cancer patients aimed at reducing morbidity or mortality from lynch syndrome in the index case or her relatives

Endometrial cancer is the first malignancy in 50% of women with Lynch syndrome, an autosomal dominant cancer-prone syndrome caused by germline mutations in genes encoding components of the DNA mismatch repair (MMR) pathway. These women (2-4% of all those with endometrial cancer) are at risk of metachronous colorectal cancer and other Lynch syndrome-associated cancers, and their first-degree relatives are at 50% risk of Lynch syndrome. Testing all women newly diagnosed with endometrial cancer for Lynch syndrome may have clinical utility for the index case and her relatives by alerting them to the benefits of surveillance and preventive options, primarily for colorectal cancer. The strategy involves offering germline DNA mutation testing to those whose tumour shows loss-of-function of MMR protein(s) when analysed for microsatellite instability (MSI) and/or by immunohistochemisty (IHC). In endometrial tumours from unselected patients, MSI and IHC have a sensitivity of 80-100% and specificity of 60-80% for detecting a mutation in an MMR gene, though the number of suitable studies for determining clinical validity is small. The clinical validity of strategies to exclude those with false-positive tumour test results due to somatic hypermethylation of the MLH1 gene promoter has not been determined. Options include direct methylation testing, and excluding those over the age of 60 who have no concerning family history or clinical features. The clinical utility of Lynch syndrome testing for the index case depends on her age and the MMR gene mutated: the net benefit is lower for those diagnosed at older ages and with less-penetrant MSH6 mutations. To date, women with these features are the majority of those diagnosed through screening unselected endometrial cancer patients but the number of studies is small. Similarly, clinical utility to relatives of the index case is higher if the family's mutation is in MLH1 or MSH2 than for MSH6 or PMS2. Gaps in current evidence include a need for large, prospective studies on unselected endometrial cancer patients, and for health-economic analysis based on appropriate assumptions.

Current Lynch syndrome tumor screening practices: a survey of genetic counselors

An electronic survey of the National Society of Genetic Counselors Cancer Special Interest Group was conducted in July 2011 to assess Lynch syndrome tumor screening programs and identify barriers to implementation. Over half of respondents (52.8 %) reported having a routine Lynch syndrome tumor screening protocol for newly diagnosed colon and/or endometrial cancers, and approximately half of these used a universal approach. There was an increase in the number of those screening over time, especially in the past 3 years. Tumor screening methods varied; 34/53 (64.2 %) started with immunohistochemistry, 11/53 (20.8 %) started with microsatellite instability testing and 8/53 (15.1 %) performed both on newly diagnosed colorectal tumors. Just 21.7 % (23/106) of respondents indicated they have a tumor screening program in place for newly diagnosed endometrial cancers. Written consent is rarely obtained (7.1 %) and the method of how results were returned to the patient was variable among respondents. Prevalent barriers to implementation were concern about cost, bringing key players together and convincing medical staff of the necessity. Use of Lynch syndrome tumor screening is in clinical practice, but protocols vary widely. This survey provides a glimpse of current practices and common barriers, and identifies the need for tumor screening algorithms with outcomes data.

BRCA1 immunohistochemistry in a molecularly characterized cohort of ovarian high-grade serous carcinomas

BRCA1 and BRCA2 dysfunction, frequently seen in high-grade serous ovarian carcinomas, often results from germline mutations, somatic mutations, and promoter methylation. Identification of tumors with BRCA defects has therapeutic and prognostic implications. Identifying germline BRCA mutations is also important given the increased risk for hereditary breast and ovarian carcinoma. Our goal was to assess whether immunohistochemical analysis (IHC) for BRCA1 is an effective method for the detection of BRCA1 dysfunction in molecularly characterized high-grade ovarian serous carcinoma. We identified 43 high-grade ovarian serous carcinomas with known events in BRCA1 and BRCA2 included in The Cancer Genome Atlas Project. BRCA1 stain was first assessed without knowledge of the BRCA status, and a semiquantitative assessment for intensity and amount of staining was performed. The stains were reevaluated and divided into 3 categories (retained, loss, and equivocal) on the basis of correlation with genotyping data. Presence of retained BRCA staining was considered normal, whereas the other patterns, including equivocal staining or loss of staining, were considered abnormal. Two pathologists, blinded to the BRCA status, then scored 2 sets of validation cases selected on the basis of available molecular data-1 with only germline mutation status available (n=31) and 1 with comprehensive genomic data (n=39). The pathologists agreed 88% of the time in the training set and 91% in the validation sets. In the training set, abnormal BRCA staining was seen in 24 cases, of which 21 (87%) showed BRCA1 genetic abnormalities, 1 showed BRCA2 mutations, and 2 showed no BRCA abnormalities. Abnormal BRCA1 staining was noted in all 5 cases with BRCA1 germline mutations, in 3 (60%) of 5 with BRCA1 somatic mutations, and in 13 (93%) of 14 with BRCA1 promoter methylation. The 2 validation sets included 70 additional patients, and all cases with germline BRCA1 mutations (n=11) showed abnormal BRCA1 staining. Tumors with BRCA1 promoter methylation also showed abnormal staining in 6 (86%) of 7 cases. In the entire study, no cases with BRCA1 germline mutation showed intact immunostaining (negative predictive value=100%). This study shows that BRCA1 IHC is well correlated with molecular events in ovarian carcinoma. Considering the high negative predictive value for germline mutations, BRCA1 IHC appears to be an effective approach to stratify patients for germline genetic testing and to detect other mechanisms of BRCA1 dysfunction in high-grade serous ovarian carcinomas.

Are women with endocervical adenocarcinoma at risk for lynch syndrome? Evaluation of 101 cases including unusual subtypes and lower uterine segment tumors

It is well documented that endometrial and ovarian carcinoma are associated with Lynch syndrome (LS), but the association, if any, between endocervical carcinoma and LS has not been fully evaluated. The relationship between endocervical carcinoma and LS is particularly relevant, given the apparent affinity of LS-associated endometrial carcinomas for the lower uterine segment and the attendant difficulties in determining tumor origin at this site. In this study, we examined mismatch repair (MMR) protein expression (MLH1, MSH2, MSH6, and PMS2) in 60 endocervical adenocarcinomas, including variants (minimal deviation adenocarcinoma, mesonephric adenocarcinoma, adenosquamous carcinoma, clear cell carcinoma) and a series of well-characterized lower-uterine segment carcinomas of known endocervical or endometrial origin (n=41). Two of the lower uterine segment tumors occurred in risk-reducing hysterectomy specimens from known LS patients. All endocervical adenocarcinomas including variants and lower uterine segment endocervical tumors (1 from a known LS patient) were proficient in all 4 MMR proteins. In contrast, 2/20 (10%) lower uterine segment endometrial cancers were deficient in at least 1 MMR (1 from a known LS patient). These data provide evidence that, unlike endometrial and ovarian adenocarcinoma, there is no association between LS and endocervical carcinoma. MMR testing is prudent in lower uterine segment tumors in women with possible LS, especially those for which definitive site of origin cannot be determined.

Acceptance of genetic counseling and testing in a hospital-based series of patients with gynecological cancer

Referral of patients with endometrial (EC) and/or ovarian cancer (OC) for genetic counseling is based on age at diagnosis and family history. Many patients with hereditary cancers are missed by following this strategy. We determined acceptance and mutation detection rate of offering genetic counseling and testing to unselected EC and OC patients. Therefore, in 2007, EC and OC patients were invited for genetic counseling and testing. Patients were asked for their reasons to accept or decline. Nineteen out of fifty-two EC patients (36 %) and twenty-two out of thirty-five OC patients (63 %) accepted genetic counseling, mainly to receive risk assessment for themselves and relatives. Counseling was declined mainly because patients did not want more tests or had no relatives for whom it was relevant. Eighteen out of nineteen EC patients (95 %) and twenty out of twenty-two OC patients (91 %) underwent genetic testing. One EC patient carried an MSH6 mutation (mutation detection rate: 6 %). BRCA1/2 mutations were found in two out of twenty OC patients (10 %). Eleven patients (29 %) received surveillance recommendations for themselves and their relatives. Finally, family history recorded by the gynecologist was compared to that taken by the clinical geneticist. Gynecologists reported family history in ten out of forty-one participants (24 %). In conclusion, genetic counseling and testing are acceptable to patients with OC and/or EC. The 10 % BRCA1/2 mutation detection rate and underreporting of family history by gynecologists warrant referral for genetic counseling for all OC patients, followed by BRCA1/2 testing if indicated. We recommend that microsatellite instability and immunohistochemical analysis be performed in all EC patients, followed by genetic counseling if appropriate. These strategies will lead to better cancer prevention in gynecological cancer patients and their relatives.

Identifying Lynch syndrome in patients with endometrial carcinoma: shortcomings of morphologic and clinical schemas

It has been suggested that reflex testing for Lynch syndrome (LS) using mismatch repair immunohistochemistry and/or microsatellite instability analysis in newly diagnosed colorectal carcinoma (CRC) patients is an emerging standard of care in the United States. The risk of gynecologic malignancy in women with LS approaches and even exceeds that of CRC. Furthermore, gynecologic malignancies are often the sentinel cancers in these patients. There is significant variation in practice, but some groups have similarly recommended deployment of reflex testing strategies in patients presenting with endometrial cancer (EC). The College of American Pathologists has stated that pathologists should recognize the histologic and clinical features that should prompt at least a recommendation for mismatch repair testing. Morphologic and clinical schemas in EC to identify microsatellite unstable/LS tumors are less refined than the colon-centric schemas (Amsterdam, Bethesda, and MsPath). Studies of LS EC are few and interpretation is limited by recruitment strategies and the myriad of definitions and study designs used. Although serous cell type is used to triage ovarian cancer patients for BRCA screening, cell type correlation in LS is less certain but seems to involve a spectrum of cell types. We review the morphologic and clinical features/schemas in LS EC and highlight limitations of restrictive aged-based screening strategies, uncertainty in current clinical schemas and equivocal results of morphologic studies of LS EC. With uncertainty of histologic and clinical schemas, and following developments in CRC, reflex testing of all/vast majority of newly diagnosed EC for LS should be considered.

Use of mismatch repair immunohistochemistry and microsatellite instability testing: exploring Canadian practices

BACKGROUND

The mismatch repair (MMR) status of tumors is being increasingly recognized as a prognostic, predictive, and possible germline predisposition/Lynch syndrome (LS) biomarker in colorectal cancer and other cancer types, particularly in endometrial cancer. Current methods (clinical history and tumor morphology) to predict MMR deficiency (dMMR) are suboptimal, and implementation of reflex laboratory testing of appropriate tumors has been recommended, a strategy requiring test standardization and clinical coordination.

METHODS

Two web-based questionnaires were administered, a general and a specialist laboratory questionnaire, to establish the availability of such tests, requisite clinical/pathology integration, current mode of test initiation, reporting and recommendation practices, and education and attitudes among pathologists. Technical aspects were reviewed on the basis of specialist laboratory practice.

RESULTS

Of 76 respondents, 21.5% were unaware or were uncertain whether they had access to MMR immunohistochemistry. Although 78.9% of respondents had access to such testing, an integrated approach to the identification of patients with LS is lacking, being limited to just 9 centers. The majority (70%) of testing is clinician initiated, with variable implementation of reflex testing and divergent practices in recommendation to test. Standardized reporting is lacking in many centers. Education on MMR in endometrial cancer is poor compared with that in colorectal cancer (P<0.0001).

INTERPRETATION

This multicenter questionnaire highlights heterogenous practices in dMMR testing and LS identification, both in clinical terms and with regard to technical aspects of testing. An integrated multidisciplinary approach is lacking, and there is a need to educate physicians and resolve ethical issues. A Canadian consensus statement and national guidelines on dMMR testing are urgently needed, requiring input from pathologists, clinicians, and genetic counselors.

Performance of PREMM(1,2,6), MMRpredict, and MMRpro in detecting Lynch syndrome among endometrial cancer cases

PURPOSE

Lynch syndrome accounts for 2-5% of endometrial cancer cases. Lynch syndrome prediction models have not been evaluated among endometrial cancer cases.

METHODS

Area under the receiver operating curve (AUC), sensitivity and specificity of PREMM(1,2,6), MMRpredict, and MMRpro scores were assessed among 563 population-based and 129 clinic-based endometrial cancer cases.

RESULTS

A total of 14 (3%) population-based and 80 (62%) clinic-based subjects had pathogenic mutations. PREMM(1,2,6), MMRpredict, and MMRpro were able to distinguish mutation carriers from noncarriers (AUC of 0.77, 0.76, and 0.77, respectively), among population-based cases. All three models had lower discrimination for the clinic-based cohort, with AUCs of 0.67, 0.64, and 0.54, respectively. Using a 5% cutoff, sensitivity and specificity were as follows: PREMM(1,2,6), 93% and 5% among population-based cases and 99% and 2% among clinic-based cases; MMRpredict, 71% and 64% for the population-based cohort and 91% and 0% for the clinic-based cohort; and MMRpro, 57% and 85% among population-based cases and 95% and 10% among clinic-based cases.

CONCLUSION

Currently available prediction models have limited clinical utility in determining which patients with endometrial cancer should undergo genetic testing for Lynch syndrome. Immunohistochemical analysis and microsatellite instability testing may be the best currently available tools to screen for Lynch syndrome in endometrial cancer patients.

Ovarian endometrioid adenocarcinoma: incidence and clinical significance of the morphologic and immunohistochemical markers of mismatch repair protein defects and tumor microsatellite instability

A subset of women with uterine cancer exhibiting defective mismatch repair (MMR) proteins and microsatellite instability (MSI) may have Lynch syndrome, which also confers a risk for colorectal cancer and other cancers in the patient and in her family. Screening algorithms based on clinical and pathologic criteria are effective in determining which patients with uterine cancer are most likely to benefit from definitive genetic testing for Lynch syndrome. Ovarian cancer, particularly endometrioid adenocarcinoma, is also associated with Lynch syndrome, although the risk is much smaller than for uterine cancer. This study evaluated whether the morphologic criteria [tumor-infiltrating lymphocytes (TILs), peritumoral lymphocytes (PTLs), dedifferentiated morphology)] currently used to screen uterine cancer for further Lynch syndrome testing can be applied to ovarian cancer. Among 71 patients with pure ovarian endometrioid adenocarcinoma treated at a single institution, 13% had a tumor with TILs, 3% had PTLs, and none had dedifferentiated morphology. Overall, 10% of tumors had abnormal MMR protein status, defined as complete immunohistochemical loss of expression of MLH1, MSH2, MSH6, and/or PMS2. Each of these tumors with abnormal MMR status demonstrated MSI using a polymerase chain reaction-based assay evaluating 5 mononucleotide repeat markers. No relationship was found between patient age, TILs, PTLs, or a spectrum of other morphologic variables and MMR protein status/MSI. Only 1/7 tumors with abnormal MMR/MSI had TILs/PTLs. Among 14 patients who died, 12 (86%) had normal MMR status. Among 7 patients with tumors with abnormal MMR/MSI, 5 (71%) were alive without disease. Concurrent uterine tumor was present in 5/7 patients whose ovarian tumor had abnormal MMR/MSI. This study suggests that the morphologic criteria used to screen patients with uterine cancer for further Lynch syndrome testing are not applicable in patients with ovarian cancer. Although abnormal MMR/MSI did not carry prognostic value in this study, it did predict the involvement of the uterus by the tumor. Thus, in patients with ovarian endometrioid adenocarcinoma who undergo uterus-sparing surgery, abnormal MMR/MSI should prompt further diagnostic evaluation of the endometrium for tumor.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

Endometrial cancer patients and compliance with genetic counseling: room for improvement

INTRODUCTION

Immunohistochemistry (IHC) for the presence or absence of DNA mismatch repair (MMR) proteins in tumor samples is a quick and relatively inexpensive method to screen for Lynch syndrome (LS). At our institution we have found that >20% of patients lack expression of MMR proteins and >10% would be expected to benefit from genetic counseling (GC). However, compliance with referral to GC is poor. Therefore, we set out to analyze the reasons for noncompliance, hypothesizing that it could be due to a perception of a low risk for developing other cancers.

METHODS

All patients with endometrial cancer between 2007 and 2009 were identified. Patients with absence of MMR protein expression who would be expected to benefit from GC were identified. These patients were sent a questionnaire assessing the utilization of GC services as well as their perception of LS and Lynch-associated cancers.

RESULTS

Forty-seven patients out of 384 were identified who would have been expected to benefit from GC. Of the responders, 20 patients (77%) reported that they were referred by their physician for GC, of which 9 saw a genetic counselor, 8 had genetic testing, and 3 mutations were detected. The primary reason for not seeing a genetic counselor was no insurance coverage/cost of the visit followed by anxiety for the results. Nine patients stated that the patient/family did not want to know information regarding cancer risk. As compared to the general population 35% thought their risk of having LS was higher, 12% thought it was the same, 15% lower, and 38% was unsure. Forty-six percent of patients thought the risk of colon cancer was higher than background risk, and 26% thought it was the same.

CONCLUSION

Most patients underestimate their risk of LS associated heritable cancer. Physicians should pay more attention to family history and IHC in order to refer patients appropriately. In addition, more verbal and written information may enable patients to accurately assess their cancer risk. This could further improve compliance with genetic counseling and detection of Lynch syndrome.

Testing women with endometrial cancer to detect Lynch syndrome

PURPOSE

Women with endometrial cancer as a result of Lynch syndrome may not be identified as such by Amsterdam II criteria. We estimated the costs and benefits of different testing criteria to identify Lynch syndrome in women with endometrial cancer.

METHODS

We developed a Markov Monte Carlo simulation model to compare six criteria for Lynch syndrome testing for women with endometrial cancer: Amsterdam II criteria; age younger than 50 years with at least one first-degree relative having a Lynch-associated cancer at any age (FDR); immunohistochemistry (IHC) triage if age younger than 50 years; IHC triage if age younger than 60 years; IHC triage at any age if 1 FDR; and IHC triage of all endometrial cancers. Net health benefit was life expectancy, and primary outcome was the incremental cost-effectiveness ratio (ICER). The model estimated the number of new colorectal cancers associated with each strategy.

RESULTS

IHC triage of women with endometrial cancer having at least 1 FDR yielded a favorable ICER of $9,126 per year of life gained. This strategy would subject fewer cases to IHC but identify more mutation carriers than age thresholds of 50 or 60 years. IHC triage of all endometrial cancers could identify the most mutation carriers and prevent the most colorectal cancers but at considerable cost ($648,494 per year of life gained).

CONCLUSION

IHC triage of women with endometrial cancer at any age having at least 1 FDR with a Lynch-associated cancer is a cost-effective strategy for detecting Lynch syndrome.