James M Gudgeon1, Michael W Varner2, Mia Hashibe3, Marc S Williams4. 1. Intermountain Healthcare, Salt Lake City, UT, United States of America. Electronic address: jim.gudgeon@imail.org. 2. University of Utah School of Medicine, Salt Lake City, UT, United States of America; Obstetrics and Gynecology, University of Utah Health Sciences Center, Salt Lake City, UT, 30 North 1900 East, Salt Lake City, Utah, 84132. Electronic address: michael.varner@hsc.utah.edu. 3. Huntsman Cancer Institute, Salt Lake City, UT, United States of America; Division of Public Health, Department of Family & Preventive Medicine, University of Utah School of Medicine, Huntsman Cancer Institute, 2000 Circle of Hope, Salt Lake City, UT, 84112. Electronic address: mia.hashibe@utah.edu. 4. Geisinger Health System, Danville, PA, United States of America; Genomic Medicine Institute, Geisinger Health System, 100 N Academy Dr., Mail Stop 26-20, Danville, PA 17822-2620. Electronic address: mswilliams1@geisinger.edu.
Abstract
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.
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.
Authors: Jing Hao; Dina Hassen; James M Gudgeon; Susan R Snyder; Heather Hampel; Marc S Williams; Ravi N Sharaf; Christine Y Lu; Janet L Williams; Victoria Schlieder; Alanna Kulchak Rahm Journal: J Pers Med Date: 2021-12-02