BLOOD TESTS FOR CANCERS of the colon, prostate, and ovaries are often inaccurate. One problem: Normal, non-cancer cells may also bear the protein markers picked up by the tests. Searching for better markers, scientists at Matritech Inc. in Cambridge, Mass., and at Johns Hopkins University have identified a dozen so-called nuclear matrix proteins (NMPs). Each one is specific to a single type of cancer and is not found in any other cell. The first NMP test, for bladder cancer, goes on sale in Europe next month.
Detection is just the beginning, says Matritech Chairman and Chief Executive Stephen D. Chubb. If the proteins regulate tumor growth, drugs should be able to block their function and slow the cancer. Unlike existing cancer drugs that attack all rapidly dividing cells, NMP therapies should leave healthy cells untouched. Now, backed by a grant from the National Cancer Institute, Matritech hopes to clone the gene that expresses an NMP specific to prostate cancer.