Muir-Torre syndrome appropriate use criteria: Effect of patient age on appropriate use scores

Background: Muir-Torre syndrome (MTS) is a rare inherited syndrome, with an increased risk of sebaceous and visceral malignancy. Prior reports suggest screening for mismatch repair (MMR) deficiency may be warranted in patients <50 years and when sebaceous neoplasms are located on a non-head and neck location. Previously, appropriate use criteria (AUC) were developed for clinical scenarios in patients >60 years concerning the use of MMR protein immunohistochemistry (MMRP-IHC). This analysis explores the appropriateness of testing in patients ≤60 years. Methods: Panel raters from the AUC Task Force rated the use of MMRP-IHC testing for MTS for previously rated scenarios with the only difference being age. Results: Results verify the previously developed AUC for the use of MMRP-IHC in neoplasms associated with MTS in patients >60 years. Results also show that in patients ≤60 years with a single sebaceous tumor on a non-head and neck site, MMRP-IHC testing should be considered. Testing can also be considered with a 2-antibody panel on periocular sebaceous carcinoma in younger patients. Conclusions: Our findings align with known evidence supporting the need to incorporate clinical parameters in identifying patients at risk for MTS, with age being a factor when considering MMRP-IHC testing.