A new system of cancer classification has been proposed that defines cancers according to genetic and molecular features rather than by their tissue of origin, following an analysis of molecular data from over 3,500 samples of 12 different cancer types.
Presented in the journal Cell, the new system would reclassify one in ten cancer patients from the current tissue-of-origin based system. Researchers used data from the Cancer Genome Atlas (TCGA) project and identified 11 ‘integrated subtypes’ and although five were almost identical to their tissue-of-origin counterparts, others were more similar at the molecular and genetic level than at the tissue level.
Researchers hope that the new system of classification will improve the accuracy for the prediction of clinical outcomes along with potentially developing better treatments and affecting the recruitment of patients into clinical trials. The researchers highlight the example of bladder cancers, where samples fall into three different integrated subtypes with one subtype almost identical to lung adenocarcinoma. They cite that this may explain why bladder cancer patients have different results when treated with the same systematic therapy.
In detailing the impact of the research, one of the lead authors, Professor Chris Benz of the Buck institute for Research on Aging, said it: “…provides a massive new data resource for the further exploration as well as a comprehensive list of the molecular features distinguishing each of the newly described cancer classes”.
He hopes that future studies will validate the findings and additional samples and tumour types will extend the integrated analysis, but states that this study: “…will ultimately provide the biologic foundation for that era of personalised cancer treatment that patients and clinicians eagerly await”.