I am affiliated with a company that has just introduced a laboratory
test to identify the tissue of origin for metastatic cancers. In November 2007, a team of pathologists from three cancer centers presented a poster at the Association of Molecular Pathologist meeting that showed the test successfully identified the tissue of origin for 8 out of 10 previously diagnosed as CUP. (It also reports the results of a large clinical validation study performed on more than 470 specimens). I thought this might be useful new information for this
discussion. A copy of the poster is at:
http://www.pathworkdx.com/news/AMPAbstract5.pdf
Although I am not an MD, my life-work is in advancing the science of cancer diagnosis - bringing new genomic technologies into the clinical laboratory. Hope this helps.
Warm regards, GGA