This is a non-randomized Phase II study. Patients determined at initial diagnosis to have a carcinoma of unknown primary site (CUP) will have their treatment selected with the use of a molecular profiling assay. The assay will be performed on paraffin-embedded tumor tissue from a biopsy specimen. Patients given specific diagnoses (e.g., lung, pancreas, colon, breast, renal cell, prostate and ovarian cancer) will receive treatment regimens of proven activity. If no specific diagnosis is made with the molecular profiling assay, empiric chemotherapy with paclitaxel, carboplatin, bevacizumab and erlotinib will be administered.