Worldwide Practice Patterns in Lynch Syndrome Diagnosis and Management, Based on Data From the International Mismatch Repair Consortium

Creation of a Quality Payment Program Measure for Mismatch Repair or Microsatellite Instability Biomarker Testing Status in Colorectal, Endometrial, Gastroesophageal, or Small Bowel Carcinoma

CONTEXT.—

Quality measures that are supported by evidence-based clinical practice guidelines are preferred for assessing the quality of pathologists' practices. Careful testing of a measure ensures that scores obtained by that measure reflect the quality of a pathologist's practice.

OBJECTIVE.—

To specify a new quality measure and to demonstrate through testing that it is suitable for measuring pathologists' appropriate incorporation of information regarding microsatellite instability (MSI) and/or mismatch repair (MMR) status in pathology reports for colorectal, endometrial, gastroesophageal, and small bowel carcinoma.

DESIGN.—

The College of American Pathologists collaborated with the American Gastroenterological Association to specify and test the new measure. Face validity testing was used to investigate the validity of the measure. Feasibility testing was conducted to understand if data elements required by the measure specification were readily accessible. Signal-to-noise analysis was used to characterize the measure's reliability.

RESULTS.—

Guideline recommendations for MSI and/or MMR testing supported specifications for the measure. Face validity testing indicated that the measure could distinguish the quality of care provided. Data elements required by the measure specification were found to be accessible, which supported the measure's feasibility. Reliability testing showed that differences in measure score were attributable to real differences in performance rather than random variation in scoring.

CONCLUSIONS.—

The Mismatch Repair or Microsatellite Instability Biomarker Testing Status in Colorectal Carcinoma, Endometrial, Gastroesophageal, or Small Bowel Carcinoma measure was appropriately specified, and testing demonstrated that it is well suited for characterizing the quality of pathologists' communication of MMR and/or MSI status.

Diagnosis of patients with Lynch syndrome lacking the Amsterdam II or Bethesda criteria

BACKGROUND

Lynch Syndrome (LS) is an autosomal dominant inheritance disorder characterized by genetic predisposition to develop cancer, caused by pathogenic variants in the genes of the mismatch repair system. Cases are detected by implementing the Amsterdam II and the revised Bethesda criteria, which are based on family history.

MAIN BODY

Patients who meet the criteria undergo posterior tests, such as germline DNA sequencing, to confirm the diagnosis. However, these criteria have poor sensitivity, as more than one-quarter of patients with LS do not meet the criteria. It is very likely that the lack of sensitivity of the criteria is due to the incomplete penetrance of this syndrome. The penetrance and risk of developing a particular type of cancer are highly dependent on the affected gene and probably of the variant. Patients with variants in low-penetrance genes have a lower risk of developing a cancer associated with LS, leading to families with unaffected generations and showing fewer clear patterns. This study focuses on describing genetic aspects of LS cases that underlie the lack of sensitivity of the clinical criteria used for its diagnosis.

CONCLUSION

Universal screening could be an option to address the problem of underdiagnosis.

PREMM5 distinguishes sporadic from Lynch syndrome-associated MMR-deficient/MSI-high colorectal cancer

Current algorithms for diagnosing Lynch syndrome (LS) include multistep molecular tumor tests to distinguish LS-associated from sporadic colorectal cancer (CRC), which add cost and complexity to the evaluation. We hypothesized that PREMM5, a clinical LS prediction tool, could be an alternative approach to screen for LS, thereby lessening the need for specialized molecular diagnostics. We reviewed a consecutively ascertained institutional cohort of 1058 CRC patients on whom pathologic and clinical data were available, including prior LS germline testing. Data from MMR-D/MSI-H CRC patients were reviewed and PREMM5 scores were calculated for each individual. Using a PREMM5 score cutoff ≥ 2.5% to characterize the need for germline testing, we determined the rate of pathogenic/likely pathogenic germline variants (PGVs) in LS genes in patients with PREMM5 scores ≥ 2.5% versus < 2.5%. Sensitivity and negative predictive values (NPV) of PREMM5 were calculated for all MMR-D/MSI-H CRC patients, and those with MLH1-deficient CRC. MMR IHC and/or MSI results were available on 572/1058 cases. We identified 74/572 (12.9%) cases as MMR-D/MSI-H, of which 28/74 (37.8%) harbored a LS PGV. 11/49 (22.4%) patients with MLH1-deficient CRC harbored a LS PGV. PREMM5 had 100% sensitivity (95% CI: 87.7-100 for any MMR-D/MSI-H; 95% CI: 71.5-100 for MLH1-deficient CRC) and 100% NPV (95% CI: 83.2-100 for any MMR-D/MSI-H; 95% CI: 82.4-100 for MLH1-deficient CRC) for identifying LS PGVs in these cohorts. PREMM5 accurately distinguishes LS- from non-LS-associated MMR-D/MSI-H CRC without additional somatic molecular testing. These findings are particularly relevant for limited-resource settings where advanced molecular diagnostics may be unavailable.

Development of an Electronic Health Record-Based Clinical Decision Support Tool for Patients With Lynch Syndrome

PURPOSE

To develop an electronic health record (EHR)-based clinical decision support (CDS) tool to promote guideline-recommended cancer risk management among patients with Lynch syndrome (LS), an inherited cancer syndrome that confers an increased risk of colorectal and other cancer types.

MATERIALS AND METHODS

We conducted a cross-sectional study to determine the baseline prevalence and predictors of guideline-recommended colonic surveillance and annual genetics program visits among patients with LS. Multivariable log-binomial regressions estimated prevalence ratios (PRs) of cancer risk management adherence by baseline sociodemographic and clinical characteristics. These analyses provided rationale for the development of an EHR-based CDS tool to support patients and clinicians with LS-related endoscopic surveillance and annual genetics program visits. The CDS leverages an EHR platform linking discrete genetic data to LS Genomic Indicators, in turn driving downstream clinician- and patient-facing CDS.

RESULTS

Among 323 patients with LS, cross-sectional adherence to colonic surveillance and annual genetics program visits was 69.3% and 55.4%, respectively. Patients with recent electronic patient portal use were more likely to be adherent to colonic surveillance (PR, 1.67; 95% CI, 1.11 to 2.52). Patients more recently diagnosed with LS were more likely to be adherent to annual genetics program visits (PR, 0.58; 95% CI, 0.44 to 0.76 for 2-4 years; PR, 0.62; 95% CI, 0.51 to 0.75 for ≥4 compared with <2 years). Our EHR-based CDS tool is now active for 421 patients with LS throughout our health system.

CONCLUSION

We have successfully developed an EHR-based CDS tool to promote guideline-recommended cancer risk management among patients with LS.

Evaluation of Microsatellite Instability Molecular Analysis versus Immuno-Histochemical Interpretation in Malignant Neoplasms with Different Localizations

MMR gene germline mutations are considered a major genetic disorder in patients with hereditary nonpolyposis colon cancer (HNPCC) or Lynch syndrome; A total of 15% of sporadic colon carcinomas are MSI-High. MSI has also been observed in other cancers, such as endometrial, gastric, and ovarian cancer. The aim of the current study was to correlate and outline the optimal method between the molecular testing of the instability of microsatellite DNA regions (MSI status) and the loss of protein expression by immunehistochemistry (MMR). A total of 242 paraffin-embedded tissues from gastrointestinal, gynecological, genitourinary, lung, breast, and unknown primary cancer patients were analyzed for the expression of MLH1/MSH2/MSH6/PMS2 by immunohistochemistry, as well as for the molecular analysis of MSI status using PCR-based molecular fragment analysis. A total of 29 MSI-High patients were detected molecularly, while 23 patients were detected by immunohistochemistry, with rates that are comparable according to the literature. Based on the agreement coefficient of the two methods, a substantial agreement emerged (Kappa = 0.675 with standard error = 0.081, p < 0.001). Despite the substantial agreement, both methods ought to be established to determine MSI-H/dMMR status in all cancer types as a first-line screening test.

Lynch syndrome: from detection to treatment

Lynch syndrome (LS) is an inherited cancer predisposition syndrome associated with high lifetime risk of developing tumours, most notably colorectal and endometrial. It arises in the context of pathogenic germline variants in one of the mismatch repair genes, that are necessary to maintain genomic stability. LS remains underdiagnosed in the population despite national recommendations for empirical testing in all new colorectal and endometrial cancer cases. There are now well-established colorectal cancer surveillance programmes, but the high rate of interval cancers identified, coupled with a paucity of high-quality evidence for extra-colonic cancer surveillance, means there is still much that can be achieved in diagnosis, risk-stratification and management. The widespread adoption of preventative pharmacological measures is on the horizon and there are exciting advances in the role of immunotherapy and anti-cancer vaccines for treatment of these highly immunogenic LS-associated tumours. In this review, we explore the current landscape and future perspectives for the identification, risk stratification and optimised management of LS with a focus on the gastrointestinal system. We highlight the current guidelines on diagnosis, surveillance, prevention and treatment and link molecular disease mechanisms to clinical practice recommendations.

Colorectal Cancer Screening Recommendations and Outcomes in Lynch Syndrome

Screening for colorectal cancer (CRC) in Lynch syndrome enables early detection and likely cancer prevention. CRC screening guidelines have evolved from universal to gene-specific recommendations based on lifetime neoplasia risks. Regular screening for Lynch syndrome reduces CRC-related mortality; however, high CRC incidence during regular colonoscopy screening suggests the possibility of nonpolypoid carcinogenesis. Colonoscopy is the primary modality for screening for Lynch syndrome with mixed and emerging data on quality metrics, chromoendoscopy, artificial intelligence, and nonendoscopic modalities. Screening adherence varies across studies. In this review, we present the current state of CRC screening recommendations, outcomes, and modalities in Lynch syndrome.

Lynch syndrome - Hidden in Plain Sight. A commentary on the paper Lynch syndrome screening in colorectal cancer: results of a prospective two-year regional programme validating the NICE diagnostics guidance pathway across a 5.2 million population

Bowel Cancer UK estimate that 175,000 people in the UK have Lynch Syndrome, yet fewer than 5% of this number are aware that they have the condition¹ . Contemporaries to Lynch, such as the BRCA (breast cancer) gene, have become household names. Perhaps this is due to greater awareness within the medical field, the media or Angelina Jolie, yet Lynch Syndrome still lags behind in the professional and public consciousness.

Upper Gastrointestinal Lesions during Endoscopy Surveillance in Patients with Lynch Syndrome: A Multicentre Cohort Study

Simple Summary

Patients with Lynch syndrome are at increased risk of upper gastrointestinal cancer. Recommendations for upper gastrointestinal endoscopy screening vary widely with limited data supporting effectiveness. The aim of our study was to investigate yields of upper gastrointestinal endoscopy screening in a large multicentre cohort of 172 Lynch syndrome mutation carriers. In our study, upper gastrointestinal endoscopy surveillance detects frequent neoplastic lesions particularly after the age of 40 years. Ours results suggest that Lynch patients should be considered for upper gastrointestinal endoscopic and Helicobacter pylori screening.

Abstract

Background: Patients with Lynch syndrome are at increased risk of gastric and duodenal cancer. Upper gastrointestinal endoscopy surveillance is generally proposed, even though little data are available on upper gastrointestinal endoscopy in these patients. The aim of this retrospective study was to evaluate the prevalence and incidence of gastrointestinal lesions following upper gastrointestinal endoscopy examination in Lynch patients. Methods: A large, multicentre cohort of 172 patients with a proven germline mutation in one of the mismatch repair genes and at least one documented upper gastrointestinal endoscopy screening was assessed. Detailed information was collected on upper gastrointestinal endoscopy findings and the outcome of endoscopic follow-up. Results: Seventy neoplastic gastrointestinal lesions were diagnosed in 45 patients (26%) out of the 172 patients included. The median age at diagnosis of upper gastrointestinal lesions was 54 years. The prevalence of cancer at initial upper gastrointestinal endoscopy was 5% and the prevalence of precancerous lesions was 12%. Upper gastrointestinal lesions were more frequent after 40 years of age (p < 0.001). Helicobacter pylori infection was associated with an increased prevalence of gastric, but not duodenal, lesions (p < 0.001). Conclusions: Neoplastic upper gastrointestinal lesions are frequent in patients with Lynch syndrome, especially in those over 40 years of age. The results of our study suggest that Lynch patients should be considered for upper gastrointestinal endoscopic and Helicobacter pylori screening.

Gastric cancer is highly prevalent in Lynch syndrome patients with atrophic gastritis

BACKGROUND

Although gastric cancer is one of the Lynch syndrome (LS)-related tumors, the clinicopathological features of gastric cancer in patients with LS remain uncertain. To investigate the incidence risk and clinicopathological features of gastric neoplasms in LS, we conducted a retrospective cohort study in Japanese LS patients.

METHODS

LS patients with pathogenic mismatch repair (MMR) gene variants were extracted from the LS registry of the National Cancer Center Hospital, Japan. Cumulative risks of gastric neoplasm, including dysplasia and cancer, were estimated using the Kaplan-Meier method. Gastric atrophy was evaluated endoscopically and/or histologically. Immunohistochemical staining for MMR proteins was performed for all available specimens.

RESULTS

Of 118 eligible patients, 26 patients were diagnosed with 58 gastric neoplasms. The cumulative incidence of gastric neoplasm was 41.0% (95% confidence interval, 26.9-55.0) at the age of 70. Of these, 13 (50%) patients developed synchronous and/or metachronous multiple gastric neoplasms. Among the 49 gastric neoplasms available for detailed pathological evaluation, all were associated with intestinal metaplasia. Immunohistochemically, 42 (86%) were MMR-deficient. The individuals with gastric atrophy had a significantly higher risk of developing gastric neoplasms compared with those without gastric atrophy (26 cases/54 individuals vs. 0 cases/53 individuals) (P = 0.026).

CONCLUSION

LS patients, particularly those with atrophic gastritis, are at high risk of gastric neoplasm and often develop multiple tumors. Endoscopic surveillance for gastric cancer is recommended for LS patients, especially those with atrophic gastritis.

Identification and management of Lynch syndrome in the Middle East and North African countries: outcome of a survey in 12 countries

BACKGROUND

Lynch syndrome (LS), the most common inherited form of colorectal cancer (CRC), is responsible for 3% of all cases of CRC. LS is caused by a mismatch repair gene defect and is characterized by a high risk for CRC, endometrial cancer and several other cancers. Identification of LS is of utmost importance because colonoscopic surveillance substantially improves a patient's prognosis. Recently, a network of physicians in Middle Eastern and North African (ME/NA) countries was established to improve the identification and management of LS families. The aim of the present survey was to evaluate current healthcare for families with LS in this region.

METHODS

A questionnaire was developed that addressed the following issues: availability of clinical management guidelines for LS; attention paid to family history of cancer; availability of genetic services for identification and diagnosis of LS; and assessment of knowledge of LS surveillance. Members of the network and authors of recent papers on LS from ME/NA and neighbouring countries were invited to participate in the survey and complete the online questionnaire.

RESULTS

A total of 55 individuals were invited and 19 respondents from twelve countries including Algeria, Azerbaijan, Cyprus, Egypt, Iran, Jordan, Kuwait, Lebanon, Morocco, Palestine, Tunisia, and Turkey completed the questionnaire. The results showed that family history of CRC is considered in less than half of the surveyed countries. Guidelines for the management of LS are available in three out of twelve countries. The identification and selection of families for genetic testing were based on clinical criteria (Amsterdam criteria II or Revised Bethesda criteria) in most countries, and only one country performed universal screening. In most of the surveyed countries genetic services were available in few hospitals or only in a research setting. However, surveillance of LS families was offered in the majority of countries and most frequently consisted of regular colonoscopy.

CONCLUSION

The identification and management of LS in ME/NA countries are suboptimal and as a result most LS families in the region remain undetected. Future efforts should focus on increasing awareness of LS amongst both the general population and doctors, and on the improvement of the infrastructure in these countries.

Suboptimal Adherence in Clinical Practice to Guidelines Recommendation to Screen for Lynch Syndrome

BACKGROUND

Identification of Lynch syndrome (LS) followed by annual/biannual surveillance colonoscopy markedly reduces the risk of developing new colorectal cancer (CRC) among those with LS.

AIMS

(1) To determine the current practice of identifying LS in the USA and Canada, and current surveillance and management practices for those diagnosed with LS; (2) to determine whether variances in current practice are physician/region dependent or influenced by ease of access to specialist clinics.

METHODS

An online survey request was sent to practicing gastroenterologists through the Canadian Association of Gastroenterology and the American College of Gastroenterology. Fisher's exact tests were performed to determine the factors associated with screening for LS and separately for follow-up, surveillance, and management.

RESULTS

A total of 249 participants were recruited, of which 237 were gastroenterologists and included in the analysis. Less than one-third of practicing gastroenterologists indicated that their CRC patients were undergoing screening tests to identify LS. While 42% (65/153) of participants from the USA stated that their patients were undergoing universal LS screening (i.e., among all diagnosed with CRC), only 12% (6/49) of participants from Canada reported this practice (p < 0.001). There was no difference in reported practice between the physicians that do and do not have access to hereditary clinics (35% vs. 34% testing; p = 0.54). Appropriate surveillance interval to look for CRC in patients with LS was recommended by most.

CONCLUSION

This survey suggests there is a significant difference in practice between Canada and the USA in regard to identification of LS, with suboptimal practice throughout North America.