The breakdown of the immunohistochemical analyses undertaken
| PTEN | MMR proteins (MLH1, MSH2, MSH6 and PMS2) | |
| Protein(s) expression observed | 1169 (90.5%) | 1222 (94.6%) |
| Loss of protein expression | 91 (7.2%) | 33 (2.7%) |
| Failed samples | 11 (0.9%) | 16 (1.3%) |
| Could not be tested | 20 (1.5%) | 20 (1.5%) |
For each protein, the result was reported as either expression, or loss of expression. samples which could not be tested included, but were not limited to, those which were received in the laboratory following the COVID-19 lockdown of March 2020, and those where a tissue mega-block was received, rather than a standard size FFPE tissue block, which was unsuitable for testing on the Autostainer.
FFPE, formalin-fixed, paraffin-embedded; MMR, mismatch repair.