BEIJING, March 24 (Xinhuanet) -- A new test that analyzes microRNAs can tell doctors the source of some mysterious cancers and help provide a short-cut for treating them, according to media reports quoting researchers in the Nature Biotechnology Monday.　

    Nitzan Rosenfeld of Israel-based Rosetta Genomics and colleagues said their test used microRNAs, a type of genetic material that regulates genes and known to be involved in cancer, as effective biomarkers to identify where in the body a tumor started.    

    Researchers used the specific chemotherapies to identify tumors that had spread in the body from unknown sources -- a type of cancer known as "cancer of unknown primary" or CUP.

    After examining 400 samples of 22 different tumor tissues and metastases, they identified the source in two-thirds of cases, they reported.    

    Most cancers are named according to the place they first develop. But there is a group of patients with whom you can't find a primary tumor. It either acquires the ability to metastasize so early in development that primary doesn't develop. Or the primary never exists. Being able to identify the primary origin of a cancer is key to treating it.

    (Agencies)