Establishing a colorectal cancer research database from routinely collected health data: the process and potential from a pilot study.

OBJECTIVE: Colorectal cancer is a common cause of death and morbidity. A significant amount of data are routinely collected during patient treatment, but they are not generally available for research. The National Institute for Health Research Health Informatics Collaborative in the UK is developing infrastructure to enable routinely collected data to be used for collaborative, cross-centre research. This paper presents an overview of the process for collating colorectal cancer data and explores the potential of using this data source. METHODS: Clinical data were collected from three pilot Trusts, standardised and collated. Not all data were collected in a readily extractable format for research. Natural language processing (NLP) was used to extract relevant information from pseudonymised imaging and histopathology reports. Combining data from many sources allowed reconstruction of longitudinal histories for each patient that could be presented graphically. RESULTS: Three pilot Trusts submitted data, covering 12 903 patients with a diagnosis of colorectal cancer since 2012, with NLP implemented for 4150 patients. Timelines showing individual patient longitudinal history can be grouped into common treatment patterns, visually presenting clusters and outliers for analysis. Difficulties and gaps in data sources have been identified and addressed. DISCUSSION: Algorithms for analysing routinely collected data from a wide range of sites and sources have been developed and refined to provide a rich data set that will be used to better understand the natural history, treatment variation and optimal management of colorectal cancer. CONCLUSION: The data set has great potential to facilitate research into colorectal cancer.

Rectal cancer: Watch-and-wait and continuing the rectal-preserving strategy with local excision for incomplete response or limited regrowth.

BACKGROUND: Deferral of conventional surgery for rectal cancer after neo-adjuvant chemo-radiotherapy is gaining increasing interest, particularly for patients who are too frail to undergo major surgery but also those who wish to avoid the adverse effects of major surgery. We elected to undertake a pragmatic approach to include all comers in a cohort with the aim of reflecting the clinical outcomes for patients on a deferral from conventional rectal surgery pathway, treated with neo-adjuvant chemo-radiation (CRT) with or without selective local excision (LE) offered to those who failed to demonstrate a complete clinical response (cCR). METHODS: Rectal cancer patients treated with neo-adjuvant CRT were stratified to a group of complete responders to CRT on a "watch and wait" (WW) pathway and a group who were treated with an additional local excision for persistent tumour. RESULTS: Regrowth was noted in 26% (11/42) in the WW group after 2 years surveillance, disease free survival was 94.5% (80-99%) at 1 year and 74.9% (44-76.4%) at 3 years. Recurrence was noted in 45% (10/22) in the CRT + LE group, disease free survival at 1 and 3 years was 74% (53.4-88.1) and 66.2% (45.6-82.4) respectively. CONCLUSION: A WW strategy for cCR is a viable pathway in the non-operative management of rectal cancer. We found the use of CRT + LE is a useful option for those who hope to avoid surgery but caution should be exercised due to substantially higher risk of recurrence.

Exploiting differential Wnt target gene expression to generate a molecular biomarker for colorectal cancer stratification.

OBJECTIVE: Pathological Wnt pathway activation is a conserved hallmark of colorectal cancer. Wnt-activating mutations can be divided into: i) ligand-independent (LI) alterations in intracellular signal transduction proteins (Adenomatous polyposis coli, ß-catenin), causing constitutive pathway activation and ii) ligand-dependent (LD) mutations affecting the synergistic R-Spondin axis (RNF43, RSPO-fusions) acting through amplification of endogenous Wnt signal transmembrane transduction. Our aim was to exploit differential Wnt target gene expression to generate a mutation-agnostic biomarker for LD tumours. DESIGN: We undertook harmonised multi-omic analysis of discovery (n=684) and validation cohorts (n=578) of colorectal tumours collated from publicly available data and the Stratification in Colorectal Cancer Consortium. We used mutation data to establish molecular ground truth and subdivide lesions into LI/LD tumour subsets. We contrasted transcriptional, methylation, morphological and clinical characteristics between groups. RESULTS: Wnt disrupting mutations were mutually exclusive. Desmoplastic stromal upregulation of RSPO may compensate for absence of epithelial mutation in a subset of stromal-rich tumours. Key Wnt negative regulator genes were differentially expressed between LD/LI tumours, with targeted hypermethylation of some genes (AXIN2, NKD1) occurring even in CIMP-negative LD cancers. AXIN2 mRNA expression was used as a discriminatory molecular biomarker to distinguish LD/LI tumours (area under the curve >0.93). CONCLUSIONS: Epigenetic suppression of appropriate Wnt negative feedback loops is selectively advantageous in LD tumours and differential AXIN2 expression in LD/LI lesions can be exploited as a molecular biomarker. Distinguishing between LD/LI tumour types is important; patients with LD tumours retain sensitivity to Wnt ligand inhibition and may be stratified at diagnosis to clinical trials of Porcupine inhibitors.