Abstract 2854: Clinical significance of Cofilin-1 expression in pancreatic cancer
Authors: Itoyama Rumi , Nakagawa Shigeki , Yusa Toshihiko , Nakao Yosuke , Yamao Takanobu , Umezaki Naoki , Miyata Tatsunori , Okabe Hirohisa , Hayashi Hiromitsu , Imai Katsunori , Yamashita Yo-ichi , Chikamoto Akira , Baba Hideo 
Published: August 2019

Abstract
Background: Pancreatic cancer is one of the most malignant tumors. The prognosis of patients with pancreatic cancer remains poor, with a 5-year survival rate of less than 10%. Therefore, identification of new biomarkers and development of therapeutic drugs are urgent issues. As a result of genetic research using public database, we focused on Cofilin-1. In recent years, it has been revealed that cancer cells form invadopodia to destroy extracellular matrix and cause hematogenous metastasis, and it is suggested that Cofilin-1 has a key role in stabilizing the structure of the invadopodia. However the significance of Cofilin-1 expression in cancer invasion is not clear. The purpose of this study is to verify the relationship between the expression of Cofilin-1 and patient’s prognosis in pancreatic cancer.
Methods: At first, we examined the relationship between Cofilin-1 expression level and clinicopathological factors or prognosis using GSE21501 and TCGA, which are public databases of patients with pancreatic cancer. We set the cut-off value, and divided into the two groups, the high Cofilin-1 and low groups. Then, we evaluated expression of Cofilin-1 with immunohistochemical (IHC) staining in 200 pancreatic cancer patients who underwent curative surgery during April 2004 to March 2018 at the department of gastroenterological surgery, Kumamoto University. After that, we examined the relationship between Cofilin-1 expression and prognosis.
Results: In silico analyses using GSE21501 and TCGA dataset, high expression of Cofilin-1 is associated with early recurrence and poor prognosis. Then, we evaluated expression of Cofilin-1 with IHC staining using original scoring. The score is calculated by multiplying each scores classified into 4 stages from 0 to 3 in intensity of Cofilin-1 expression and area of that. 0 to 3 of the score was the low expression group (n=93), 4 to 9 is the high expression group (n=107). The result showed that high Cofilin-1 expression is associated with high occurrence of lymph node metastasis. In addition, both the relapse free and overall survivals were significantly worse in the high Cofilin-1 group. Cox proportional hazard analysis revealed that the high Cofilin-1 expression was an independent poor prognostic predictor.
Conclusion: In both silico analysis and IHC staining, high Cofilin-1 expression is associated with poor prognosis, especially high recurrence rate in patients with pancreatic cancer. Cofilin-1 may be useful as a biomarker for early recurrence in pancreatic cancer.
Citation Format: Rumi Itoyama, Shigeki Nakagawa, Toshihiko Yusa, Yosuke Nakao, Takanobu Yamao, Naoki Umezaki, Tatsunori Miyata, Hirohisa Okabe, Hiromitsu Hayashi, Katsunori Imai, Yo-ichi Yamashita, Akira Chikamoto, Hideo Baba. Clinical significance of Cofilin-1 expression in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2854.