Tumour sequencing: Evolutions and revolutions

For some years now, we have entered the genomic age of tumour genotyping from a medical point of view. Technological breakthroughs in both biology and information science now allow a genomic analysis of cancers in everyday medical practice with, in some case, a major impact on patient care not only for the choice of therapy (i.e. EGFR mutations in lung adenocarcinoma), but also for diagnosis and monitoring of the disease. Tumour genotyping is performed from formalin-fixed paraffin-embedded tissues used for diagnosis of cancer. However, new approaches have emerged, with for example the more and more spread use of "liquid biopsies". Genotyping of a gene panel implicated in carcinogenesis is now routinely performed in some cancer types, with the help of high-throughput sequencers, and it is likely that improvement of these machines will make tumour genotyping easier and more accessible in the near future. Nevertheless, the current challenge is not anymore detection of molecular alterations, but their relevant interpretation, so as to be the most useful in patient care.