Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Genomic instability, which is a hallmark of cancer, is generally thought to occur in the middle to late stages of tumourigenesis, following the acquisition of permissive molecular aberrations such as TP53 mutation or whole genome doubling. Tumours with somatic POLE exonuclease domain mutations are notable for their extreme genomic instability (their mutation burden is among the highest in human cancer), distinct mutational signature, lymphocytic infiltrate, and excellent prognosis. To what extent these characteristics are determined by the timing of POLE mutations in oncogenesis is unknown. Here, we have shown that pathogenic POLE mutations are detectable in non-malignant precursors of endometrial and colorectal cancer. Using genome and exome sequencing, we found that multiple driver mutations in POLE-mutant cancers show the characteristic POLE mutational signature, including those in genes conventionally regarded as initiators of tumourigenesis. In POLE-mutant cancers, the proportion of monoclonal predicted neoantigens was similar to that in other cancers, but the absolute number was much greater. We also found that the prominent CD8+ T-cell infiltrate present in POLE-mutant cancers was evident in their precursor lesions. Collectively, these data indicate that somatic POLE mutations are early, quite possibly initiating, events in the endometrial and colorectal cancers in which they occur. The resulting early onset of genomic instability may account for the striking immune response and excellent prognosis of these tumours, as well as their early presentation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Original publication




Journal article


J Pathol

Publication Date





283 - 296


POLE, colorectal cancer, endometrial cancer, mutation, polymerase proofreading, precursor lesion, Adenocarcinoma, Antigens, Neoplasm, CD8-Positive T-Lymphocytes, Cell Transformation, Neoplastic, Colorectal Neoplasms, DNA Polymerase II, Databases, Genetic, Endometrial Neoplasms, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Genetic Predisposition to Disease, Genomic Instability, Humans, Lymphocytes, Tumor-Infiltrating, Male, Middle Aged, Mutation, Neoplasm Grading, Neoplasm Staging, Phenotype, Poly-ADP-Ribose Binding Proteins, Tumor Microenvironment, Whole Genome Sequencing