A novel system for the classification of cancer is being devised, which will reflect the molecular subtypes and could possibly aid in better treatments in the long term.
The study is being led by the U.S. National Cancer Institute and U.S. National Human Genome Research Institute, as a part of the Cancer Genome Atlas initiative.
Leading researchers and authors from various institutes and universities are participating in the multiple institute study.
For the purpose of the study, the researchers examined the RNA, DNA and protein from over 3,500 tumor samples from 12 types of cancer. They deployed six types of different "platform technologies" to observe how the different types of tumors compared to each other. The tumors were divided into "clusters" for the study.
"We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes," per the study.
The analysis was based on the molecular and cellular features of the cancer rather than the tissues (breast, colon, kidney, bladder, lung etc.) where it originated. The findings reclassified one in 10 cancers.
"It's only ten percent that were classified differently, but it matters a lot if you're one of those patients," revealed senior author Josh Stuart, a professor of biomolecular engineering at UC Santa Cruz (UCSC).
The researchers found that three different subtypes exist for bladder cancer of which one was similar to adenocarcinoma. The study also reasserted the existence of cancer subtypes that were known, e.g. breast cancer subtypes.
The team also got a deeper understanding into the "telltale signatures of the subtypes" which would aid in the classification of a tumor merely on the basis of the mutation or gene expression data.
"Having a molecular map like this could help get a patient into the right clinical trial," added Stuart.
However, the researchers feel there is a need to dig deeper to validate the findings of the current study. Nevertheless, the analysis lays the foundation for categorizing tumors into "molecular defined subtypes."
The study has been published in the journal Cell.
