Diagnostic Mismatch Repair IHC Testing
Referral of Colorectal Cases for Diagnostic Mismatch Repair IHC
Mismatch repair (MMR) deficiency is seen in approximately 15% of
colorectal cancers and can be a feature associated with sporadic
colorectal cancer, or be caused by Lynch Syndrome.
The publication in 2014 of a revised dataset for reporting
Colorectal Cancers by The Royal College of Pathologists (April
2014) and a National Institute for Health Research (NIHR) Health
Technology Assessment (HTA) on strategies for testing for Lynch
Syndrome (September 2014) requires the development of standardised
IHC MMR testing in pre-specified groups of patients with colorectal
The Royal College of Pathologists dataset recommends MMR
immunohistochemical (IHC) testing is considered a core item for
patients under the age of 50 and in those adenocarcinomas, where
assessment of prognosis is important, with morphological features
of MMR deficiency.
More recently, NICE has published guidance
which indicates that all new diagnoses of colorectal carcinoma,
regardless of age, should be investigated either by IHC or MSI
testing, with IHC being the preferred first-line method in the
The Immunohistochemistry Laboratory within the Adult
Histopathology Department at Central Manchester University
Hospitals NHS Foundation Trust has been performing MMR IHC testing
for the consultants in Clinical Genetics for several years and it
has been proposed that this laboratory will become the regional
referral centre. The laboratory participates in the UK NEQAS ICC
(HNPCC Module) accredited EQA scheme.
In order to ensure that the testing is performed correctly
samples must conform to the criteria written out in the referral guidelines and a fully completed request form must accompany each sample.
Please refer to the flow diagram to see how the samples will be
handled once they arrive at Manchester Royal Infirmary. Please read
the information provided on the following links for the material required for IHC
testing and reporting and invoicing.
Catherine Higgins, Advanced BMS IHC
0161 276 8786
Professor Ray McMahon, Consultant Histopathologist
0161 276 8815
Dr Lucy Foster, Consultant Histopathologist
0161 276 6954
(Last updated March 14th 2017)