Juntendo Shizuoka Hospital, Japan
Title: Pfetin as a risk factor of recurrence in gastrointestinal stromal tumors
Biography: Shunsuke Sakuraba
We have proposed Pfetin as a new, strong prognostic biomarker in resected gastrointestinal stromal tumors (GISTs). Pfetin is a potassium channel protein. It is highly expressed in fetal cochlea and in the brain, consistent with the fact that the origin of GIST is Cajal cells, and neuronal cells in the gut. Pfetin was discovered by using a proteomics approach and its usefulness as a prognostic biomarker has been reported. We examine Pfetin expression immunohistochemically using paraffin-embedded tissues, and when more than 20% of tumor cells are stained with the anti-Pfetin antibody, they are considered to be Pfetin-positive. Pfetin expression and tumor metastasis were inversely related and GIST with Pfetin-negative status has a poorer prognosis than Pfetin-positive GIST. We also have reported the fact that Pfetin is an independent predictor of recurrence/metastasis for completely resected primary, localized GIST. In our study, 13 cases were Pfetin-negative and 5/13 of these cases recurred. Conversely, 32 cases were Pfetin-positive and 2/32 of these cases recurred. (p=0.002) Pfetin is a strong prognostic biomarker and useful in selecting adjuvant therapy. We reviewed literatures and summarized Pfetin in GIST.