Table 2

Statements on which consensus was achieved

StatementResponses (n)Proportion of respondents indicating ‘agree/ strongly agree’ or ‘yes’ (%)
The abbreviations that should be used to define MMR proficient and MMR deficient should be ‘pMMR’ and ‘dMMR’ as per the IARC ‘Blue Book’ volume on genetic tumour syndromes.5896
The term unexplained dMMR should be used instead of the term ‘Lynch-like syndrome’.6088
Long-range PCR analysis of PMS2 should routinely be included as part of constitutional testing of PMS2 when cancer demonstrates isolated loss of PMS2.5985
Loss of heterozygosity analysis should be routinely available when somatic next-generation sequencing of MMR genes is undertaken.5995
It is not mandatory to pursue additional investigations for patients with dMMR cancers beyond standard testing* and constitutional genetic testing in situations where prior probability of heritable cause for cancer is low.5590
The following factors should be considered in determining probability of heritable cause of dMMR cancer to guide further testing: family history, age, tumour type, pattern of protein loss, extent of investigation.5494
It is not mandatory to undertake Lynch-equivalent surveillance for probands or their first-degree relatives in situations where there is unexplained dMMR, particularly where clinical suspicion of a heritable cause is low.5696
  • *Standard testing: somatic BRAF sequencing and/or MLH1 promoter hypermethylation testing where indicated; constitutional MMR gene testing.

  • IARC, International Agency for Research on Cancer; MMR, mismatch repair.