International Journal of Gynecological Cancer | 2019
P89\u2005Implementation of a nationwide guideline to detect of women at risk for Lynch syndrome in endometrial cancer should be improved
Abstract
Introduction/Background Since 2016 routine Lynch syndrome screening (LSS) among women with endometrial cancer <70 years of age has been incorporated in a nationwide guideline. LSS consists of immunohistochemical (IHC) staining for loss of miss match repair (MMR) protein expression, extended with methylation analysis of the MLH1 promotor in case of MLH1 and PMS2 loss. Test results are discussed by the treating gynaecologist, who refers patients to a genetic counsellor (figure 1). Objective Evaluate the implementation of the Dutch guideline to screen women with endometrial carcinoma under the age of 70 years for Lynch syndrome. Methodology From the pathology database women diagnosed with EC <70 years of age, treated from 1.6.2016 - 1.6.2017, in 14 hospitals, covering about 30% of the Netherlands, were selected. Data collected regarded LS testing and outcome, and follow up. The study was approved by the institutional review boards of participating hospitals. Results In 184 out of the 205 tumours (90%) LSS was performed (table 1). Either on the endometrial biopsy 24%, the hysterectomy (70%), or on both (6%). In 42 cases (22%) MMR protein expression was lost, in 25 cases due to hypermethylation of the MLH1 promotor. LS susceptibility was discussed with 11 of the 17 patients at risk of LS (65%), all were referred for genetic counselling. Three of them declined; eight underwent germline testing for LS after counselling. In one no germline mutation was detected, two were diagnosed with a PMS2 mutation, and five with a MSH6 mutation. Conclusion The implementation of the guideline regarding LSS has been successful, though referral for genetic counselling should be improved. Gynaecologist ought to be aware of the benefits and drawbacks of knowing mutational status, and may require training in discussing this with their patients. Disclosure Nothing to disclose. Abstract P89 Table 1 Outcomes Patients with endometrial carcinoma 205 Clear cell 5 (3.5%) High risk Lynch syndrome 17 (9%) Patients screened for LS 184 (90%) undifferentiated 1 (05%) - results pending 2 (12%) Immunohistochemistry 179 (97%) FIGO stage IA 102 (55%) - known carrier 1 (6%) Microsatellite instability analysis 3 (2%) FIGO stage IB 43 (23%) - result not shared with patient 3 (17%) Hysterectomy 129 (70%) FIGO stage II 8 (4%) - referral for genetic counseling 11 (65%) Endometrial biopsy 45 (24%) FIGO stage III 10 (6%) -- refrained genetic counseling 3 (27%) Biopsy and Hysterectomy 10 (6%) FIGO stage IV 2 (1%) -- germline analysis 8 (73%) Endometrioid carcinoma 156 (85%) Unknown FIGO stage 19 (11%) ---no known mutation detected 1 (13%) Sereus carcinoma 13 (7%) Loss of MMR-expression 42 (22%) --- MSH 6 mutation 5 (62%) carcinosarcoma 7 (4%) Hypermethylation MLH1 25 (13%) --- PMS 2 mutation 2 (25%) Abstract P89 Figure 1 Nationwide dutch guideline for detecting lynch syndrome (LS) in women with endometrial cancer