Assay for Metastatic Cancers of Unknown Origin

(Mountain View, CA, US). The test is available to doctors through Quest Diagnostics' Nichols Institute (San Juan Capistrano, CA, USA), Quest's esoteric testing laboratory, which validated and introduced the test.

CUP refers to metastatic cancer in which cancer cells are found somewhere in the body but the place of origin cannot be identified from physical examination, pathologic analysis, or other diagnostic testing. CUP is estimated to represent 3-15% of newly diagnosed cancers. An estimated 70,000 new CUP patients are diagnosed each year in the United States alone and prognosis is typically poor.

"With information about the source of the cancer, physicians will be better able to determine prognosis and appropriate therapy,” said Joyce G. Schwartz, M.D., vice president and chief laboratory officer of Quest Diagnostics. "Earlier identification of the primary tumor could increase the odds of successful cancer treatment and overall survival.”

The new test is intended to help doctors identify the site of origin of 39 tumor types, establishing prognosis, and determining appropriate therapy. The test will greatly reduce the amount of time needed by pathologists and oncologists to assess CUP patients. Currently, without a true diagnostic for CUP, evaluating CUP patients using conventional approaches such as imaging, biopsy, endoscope, and lab tests is slow and expensive. Moreover, only about 25% of primary cancers are identified this way. With the new test, results will be available to doctors within two weeks.

The test uses gene-expression profiling of biopsy tissue to determine the primary tumor site. Using the patient's biopsy specimen, gene expression profiles are generated for 92 genes, using polymerase chain reaction (PCR) methodology. These profiles are compared to an in-house reference database comprising gene expression profiles from 39 known tumor types, which determines the likely site of origin. Study results show that the test provides 82% sensitivity for identifying the site of origin of unknown primary cancer and 99% specificity.




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