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

No Racial Disparities Observed Using Point-of-Care Genetic Counseling and Testing for Endometrial and Ovarian Cancer in a Diverse Patient Population: A Retrospective Cohort Study

We investigated genetic counseling and testing rates for patients with gynecologic malignancy at a tertiary care center with a large minority population. Our retrospective cohort included newly diagnosed epithelial ovarian, fallopian tube, peritoneal, or endometrial cancer patients between January 2014 and June 2022. For endometrial cancer, 373 patients were identified. A total of 207 (55%) patients were screened using mismatch repair immunohistochemistry (MMR IHC). A total of 82 (40%) had MMR deficiencies on IHC. Of these, 63 (77%) received genetic counseling. A total of 62 (98%) underwent genetic testing, and ultimately, 7 (11%) were diagnosed with Lynch syndrome (LS). The overall rate of LS was 1.9%. MMR IHC testing increased steadily, reaching 100% in 2022. For ovarian cancer, 144 patients were identified. A total of 104 (72%) patients received genetic counseling, and 99 (95%) underwent genetic testing. Rates were not influenced by race, ethnicity, insurance type, or family history of cancer. They were significantly different by cancer stage (p < 0.01). The proportion of patients who received genetic counseling increased from 47% in 2015 to 100% in 2022 (p < 0.01). Most counseling was performed by a gynecologic oncologist (93%) as opposed to a genetic counselor (6.7%). Overall, 12 (8.3%) patients were BRCA+. High rates of counseling and testing were observed with few disparities.

Real-World Data on Institutional Implementation of Screening for Mismatch Repair Deficiency and Lynch Syndrome in Endometrial Cancer Patients

Lynch syndrome is an inherited tumor syndrome caused by a pathogenic germline variant in DNA mismatch repair genes. As the leading cause of hereditary endometrial cancer, international guidelines recommend universal screening in women with endometrial cancer. However, testing for Lynch syndrome is not yet well established in clinical practice. The aim of this study was to evaluate adherence to our Lynch syndrome screening algorithm. A retrospective, single-center cohort study was conducted of all endometrial cancer patients undergoing surgical treatment at the Bern University Hospital, Switzerland, between 2017 and 2022. Adherence to immunohistochemical analysis of mismatch repair status, and, if indicated, to MLH1 promoter hypermethylation and to genetic counseling and testing was assessed. Of all 331 endometrial cancer patients, 102 (30.8%) were mismatch repair-deficient and 3 (0.9%) patients were diagnosed with Lynch syndrome. Overall screening adherence was 78.2%, with a notable improvement over the six years from 61.4% to 90.6%. A major reason for non-adherence was lack of provider recommendation for testing, with advanced patient age as a potential patient risk factor. Simplification of the algorithm through standardized reflex screening was recommended to provide optimal medical care for those affected and to allow for cascading testing of at-risk relatives.

Identifying patients with Lynch syndrome using a universal tumor screening program in an integrated healthcare system

INTRODUCTION

Lynch syndrome (LS) is associated with an increased risk of colorectal (CRC) and endometrial (EC) cancers. Universal tumor screening (UTS) of all individuals diagnosed with CRC and EC is recommended to increase identification of LS. Kaiser Permanente Northwest (KPNW) implemented a UTS program for LS among individuals newly diagnosed with CRC in January 2016 and EC in November 2016. UTS at KPNW begins with immunohistochemistry (IHC) of tumor tissue to determine loss of mismatch repair proteins associated with LS (MLH1, MSH2, MSH6, and PMS2)., IHC showing loss of MLH1 is followed by reflex testing (automatic testing) to detect the presence of the BRAF V600E variant (in cases of CRC) and MLH1 promoter hypermethylation to rule out likely sporadic cases.

MATERIALS AND METHODS

Individuals newly diagnosed with CRC and EC were identified between the initiation of the respective UTS programs and July 2018. Electronic medical records were reviewed to extract patient data related to UTS, including IHC and reflex testing results, date of referrals to the genetics department, and results of germline genetic testing for LS.

RESULTS

313 out of 362 individuals diagnosed with CRC and 61 out of 64 individuals diagnosed with EC who were eligible were screened by IHC for LS. Most (47/52 or 90%, including 46/49 CRC and 1/3 EC) individuals that were not screened by IHC only had a biopsy sample available. Fourteen individuals (3.7% overall, including 13/313 CRC and 1/61 EC) received an abnormal result after reflex testing and were referred for genetic counseling. Of these, 10 individuals (71% overall, including 9/13 CRC and 1/1 EC) underwent germline genetic testing for LS. Five individuals diagnosed with CRC were found to have pathogenic variants. in PMS2 (n = 3), MLH1 (n = 1), and MSH6 (n = 1). No pathogenic variants were identified in individuals diagnosed with EC.

CONCLUSIONS

UTS identified individuals at risk for LS. Most individuals who screened positive for LS had follow-up germline genetic testing for LS. The consistent use of biopsy samples is an opportunity to improve UTS.

Evaluation of a nationwide Dutch guideline to detect Lynch syndrome in patients with endometrial cancer

OBJECTIVE

In the Netherlands a nationwide guideline was introduced in 2016, which recommended routine Lynch syndrome screening (LSS) for all women with endometrial cancer (EC) <70 years of age. LSS consists of immunohistochemical (IHC) staining for loss of mismatch repair (MMR) protein expression, supplemented with MLH1 methylation analysis if indicated. Test results are evaluated by the treating gynaecologist, who refers eligible patients to a clinical geneticist. We evaluated the implementation of this guideline.

METHODS

From the nation-wide pathology database we selected all women diagnosed with EC < 70 years of age, treated from 1.6.2016-1.6.2017 in 14 hospitals. We collected data on the results of LSS and follow up of cases with suspected LS.

RESULTS

In 183 out of 204 tumours (90%) LSS was performed. In 41 cases (22%) MMR protein expression was lost, in 25 cases due to hypermethylation of the MLH1 promotor. One patient was known with a pathogenic MLH1 variant. The option of genetic counselling was discussed with 12 of the 15 remaining patients, of whom three declined. After counselling by the genetic counsellor nine patients underwent germline testing. In two no pathogenic germline variant was detected, two were diagnosed with a pathogenic PMS2 variant, and five with a pathogenic MSH6 variant, in concordance with the IHC profiles.

CONCLUSION

Coverage of LSS was high (90%), though referral for genetic counselling could be improved. Gynaecologists ought to be aware of the benefits and possible drawbacks of knowing mutational status, and require training in discussing this with their patients.

Variation in physician-directed immunohistochemistry screening among women with endometrial cancer

Objective

Immunohistochemistry screening is a reliable method for identifying women with endometrial cancer who are at risk for Lynch syndrome, but clinical workflows used to implement immunohistochemistry screening protocols can vary by institution. The goal of this study was to investigate variation in performance of immunohistochemistry screening when a physician order is required.

Methods

Retrospective study from an integrated healthcare system with a risk-based immunohistochemistry screening policy for Lynch syndrome from January 2015 to December 2016. Immunohistochemistry screening was indicated for all women with endometrial cancer aged <60 years and women with endometrial cancer aged ≥60 years who had a personal/family history suggestive of Lynch syndrome. However, a physician order was needed to have immunohistochemistry screening performed on the tumor specimen as our health system did not have reflex screening in the clinical workflow. Demographics and tumor characteristics were reviewed, and patients were stratified by immunohistochemistry screening status. Multivariable regression was performed to identify factors associated with immunohistochemistry performance and reported as odds ratios (ORs) with 95% confidence intervals (CIs).

Results

There were 1399 eligible patients in the study. With a required physician order, immunohistochemistry screening rates (20% overall, 34% aged <60 years) were significantly lower than previous reports (36% overall, 90% aged <60 years, p≤0.0001 for both comparisons). Significant factors associated with immunohistochemistry screening performance identified by multivariable analysis included age, race, body mass index, personal/family cancer history, diabetes, endometrioid histology, and tumor grade. Asian women were most likely to have immunohistochemistry screening (OR 1.58, 95% CI 1.07 to 2.34) whereas black women were least likely (OR 0.43, 95% CI 0.22 to 0.91).

Conclusions

Immunohistochemistry screening rates in women with endometrial cancer were lower in our health system compared with prior reports in the literature, and there were variations in screening performance according to patient age, race, and body mass index. Requiring a physician order for immunohistochemistry screening likely creates a barrier in screening uptake, therefore automated immunohistochemistry screening is recommended.