2. Division of Tranplantation Surgery, Nagoya University Hospital, Nagoya, Japan.
3. Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan.
4. Kan-Etsu Hospital,Tsurugashima, Saitama, Japan.
Anti-epidermal growth factor receptor monoclonal antibodies are approved and effective only in KRAS wild-type patients with advanced colorectal carcinoma. The present retrospective study investigated the role of KRAS gene mutations and other clinical features in patients with cancer of unknown primary site (CUP). The metastases from two male patients of an unknown primary tumor were included in this retrospective analysis. Both cases were determined cancer of unknown primary by clinicopathologic findings. The KRAS, BRAF, and PI3KCA mutational analyses were performed by means of PCR using genomic DNA for each PCR reaction. All PCR products were directly sequenced. PIK3CA mutation was found in case 1 at exon 9 in this study. This study further investigated the role of KRAS, PIK3CA, and BRAF gene mutations and clinical features for possibilities for new therapies in patients with additional CUP cases. It has been discussed protocols of EGFR blockade and gene-mutation status for extension of indication. The possibility for EGFR blockade to be effective for new indications has been revealed.
Keywords: EGFR, KRAS, cancer of unknown primary