@article {Tavaresjclinpath-2020-207346, author = {In{\^e}s Tavares and Ricardo Martins and Ilda Patr{\'\i}cia Ribeiro and Lu{\'\i}sa Esteves and Francisco Caramelo and Ana Margarida Abrantes and Rita Neves and Rui Caetano-Oliveira and Maria Filomena Botelho and Joana Barbosa de Melo and Dulce Diogo and Jos{\'e} Guilherme Tralh{\~a}o and Isabel Marques Carreira}, title = {Development of a genomic predictive model for cholangiocarcinoma using copy number alteration data}, elocation-id = {jclinpath-2020-207346}, year = {2021}, doi = {10.1136/jclinpath-2020-207346}, publisher = {BMJ Publishing Group}, abstract = {Aims Cholangiocarcinoma (CC) is a rare tumour arising from the biliary tract epithelium. The aim of this study was to perform a genomic characterisation of CC tumours and to implement a model to differentiate extrahepatic (ECC) and intrahepatic (ICC) cholangiocarcinoma.Methods DNA extracted from tumour samples of 23 patients with CC, namely 10 patients with ECC and 13 patients with ICC, was analysed by array comparative genomic hybridisation. A support vector machine algorithm for classification was applied to the genomic data to distinguish between ICC and ECC. A survival analysis comparing both groups of patients was also performed.Results With these whole genome results, we observed several common alterations between tumour samples of the same CC anatomical type, namely gain of Xp and loss of 3p, 11q11, 14q, 16q, Yp and Yq in ICC tumours, and gain of 16p25.3 and loss of 3q26.1, 6p25.3{\textendash}22.3, 12p13.31, 17p, 18q and Yp in ECC tumours. Gain of 2q37.3 was observed in the samples of both tumour subtypes, ICC and ECC. The developed genomic model comprised four chromosomal regions that seem to enable the distinction between ICC and ECC, with an accuracy of 71.43\% (95\% CI 43\% to 100\%). Survival analysis revealed that in our cohort, patients with ECC survived on average 8 months less than patients with ICC.Conclusions This genomic characterisation and the introduction of genomic models to clinical practice could be important for patient management and for the development of targeted therapies. The power of this genomic model should be evaluated in other CC populations.}, issn = {0021-9746}, URL = {https://jcp.bmj.com/content/early/2021/02/28/jclinpath-2020-207346}, eprint = {https://jcp.bmj.com/content/early/2021/02/28/jclinpath-2020-207346.full.pdf}, journal = {Journal of Clinical Pathology} }