This will be a retrospective review of 30 patients with unknown primary cancer who have had commercially available RT-PCR assays performed on biopsied tumors, in order to determine if the assay results are consistent with clinical features and useful for planning initial therapy or changing therapy.

Inclusion Criteria:

• Patients with RT-PCR testing completed since commercialization of the RT-PCR assay in 2007.

Approximately 30 patients at Tennessee Oncology with unknown primary cancer have had commercially available RT-PCR assays done on their tissue biopsy since the assay became available in 2007. These patients are the subjects of this review.