Identifying the Primary Site Using Gene Expression Profiling in Patients with Carcinoma of an Unknown Primary (CUP): A Feasibility Study from the GEFCAPI

specimens from 18 of the 22 patients (82%). In the remaining 4 cases the test could not be performed because of low RNA preservation in the specimens. Results concerning the 18 patients are reported in the table 1, with 5 suggested tumor types according to the gene expression profile and final suggested diagnosis, integrating analysis of medical history, immunohistochemistry, and type of biopsy. The median age of the patients was 54 years (range: 29–70 years). The median delay from tissue shipping to receipt of CupPrint result was 11 days (range: 1–26 days). The most common tissues of origin identified were lung cancer (22%) and colorectal cancer (17%). Of note, primary cancers which would not be adequately treated by an empiric chemotherapy regimen currently recommended in CUP (such as cisplatin-gemcitabine or carboplatin-paclitaxel) was identified in about half of the patients: kidney cancer (1), hepatocarcinoma (1), colorectal cancer (3), head and neck cancer (2), cholangiocarcinoma (1) (table 1). At least two clinical cases suggested the potential implication of adjusting treatment according to the suggested primary. The first patient, a 50-year-old woman (patient 1, table 1), presented with a swollen left inguinal lymph node. The biopsy specimen revealed an undifferentiated carcinoma, ck7–, ck20–, RE–, PS100–, EMA– (07/2008). The CupPrint suggested the diagnosis of breast cancer, melanoma, or oral carcinoma. She underwent an inguinal dissection that showed a metastasis from melanoma (PS100 and vimentin positive). The dermatological examination revealed a lesion of the skin on the left knee. Surgical excision and histology confirmed the diagnosis of a superficial melanoma, SSM level 2, 0.44 mm deep. The patient is still in remission. The second case, a 63-year-old woman, presented with swollen left supra-clavicular, mediastinal and axillary lymph nodes (patient 2, table 1). The axillary lymph node dissection revealed an epidermoid carcinoma (ck7+, 20-). The CupPrint