*Article* **Prognostic Significance of Glucose Metabolism as GLUT1 in Patients with Pulmonary Pleomorphic Carcinoma**

**Hisao Imai 1, Kyoichi Kaira 2,3,\*, Hideki Endoh 4, Kazuyoshi Imaizumi 5, Yasuhiro Goto 5, Mitsuhiro Kamiyoshihara 6, Takayuki Kosaka 7, Toshiki Yajima 2,8, Yoichi Ohtaki 8, Takashi Osaki 9, Yoshihito Kogure 10, Shigebumi Tanaka 11, Atsushi Fujita 12, Tetsunari Oyama 13, Koichi Minato 1, Takayuki Asao <sup>14</sup> and Ken Shirabe 2,8**


Received: 19 December 2019; Accepted: 28 January 2020; Published: 3 February 2020

**Abstract:** Glucose metabolism is necessary for tumor progression, metastasis, and survival in various human cancers. Glucose transporter 1 (GLUT1), in particular, plays an important role in the mechanism of 18F-FDG (2-[18F]-fluoro-2-deoxy-d-glucose) within tumor cells. However, little is known about the clinicopathological significance of GLUT1 in patients with pulmonary pleomorphic carcinoma (PPC). Adenocarcinoma, squamous cell carcinoma, adenosquamous cell carcinoma, poorly differentiated carcinoma, large cell carcinoma, and others were identified as epithelial components, and spindle-cell type, giant-cell type, and both spindle- and giant-cell types were identified as sarcomatous components. This study was performed to determine the prognostic impact of GLUT1 expression in PPC. Patients with surgically resected PPC (n = 104) were evaluated by immunohistochemistry analysis to detect GLUT1 expression and determine the Ki-67 labeling index using specimens of the resected tumors. GLUT1 was highly expressed in 48% (50/104) of all patients, 42% (20/48) of the patients with an adenocarcinoma component, and 53% (30/56) of the patients with

a nonadenocarcinoma component. High expression of GLUT1 was significantly associated with advanced stage, vascular invasion, pleural invasion, and tumor cell proliferation as determined by Ki-67 labeling. GLUT1 expression and tumor cell proliferation were significantly correlated according to the Ki-67 labeling in all patients (Spearman's rank; r = 0.25, *p* < 0.01). In multivariate analysis, GLUT1 was identified as a significant independent marker for predicting a poor prognosis. GLUT1 is an independent prognostic factor for predicting the poor prognosis of patients with surgically resected PPC.

**Keywords:** pulmonary pleomorphic carcinoma; prognostic factor; glucose transporter 1
