Original contribution High nuclear protein kinase Cθ expression may correlate with disease recurrence and poor survival in oral squamous cell carcinoma ☆ Pei-Yi Chu MD a,b , Nicholas Chung-Heng Hsu BS c , Hui-Chun Tai MD d , Chung-Min Yeh MS d , Shu-Hui Lin MS d , Ming-Feng Hou MD e,f , Kun-Tu Yeh MD d,e,g, ⁎ a Department of Pathology, St. Martin De Porres Hospital, Chiayi 600, Taiwan b Department and Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan c Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan d Department of Pathology, Changhua Christian Hospital, Changhua 500, Taiwan e Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan f Cancer Center, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan g School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan Received 24 March 2011; revised 2 May 2011; accepted 4 May 2011 Keywords: Oral cancer; Protein kinas Cθ; Overall survival; Recurrence Summary Protein kinase Cs play important roles in many biological processes and tumorigenesis. This study examined the expression of protein kinase Cθ and assessed its significance in patients with oral squamous cell carcinoma. Immunohistochemical staining was carried out to investigate the expression of protein kinase Cθ in 59 cases of oral squamous cell carcinoma. The results were correlated with clinical characteristics and outcome of patients. Diffuse cytoplasmic protein kinase Cθ was identified in 53 (89.8%) of the 59 oral squamous cell carcinoma cases, and the expression was not statistically associated with any clinicopathologic parameter. Twenty (40.7%) of the 59 oral squamous cell carcinoma cases exhibited nuclear expression of protein kinase Cθ with different grade of intensity. χ 2 analysis indicated that high nuclear protein kinase Cθ expression correlated significantly with shorter 24-month survival (P = .043) and disease recurrence (P = .019). The Kaplan-Meier method also showed that high nuclear expression of protein kinase Cθ was significantly associated with poor overall survival (P = .034) and shorter time to recurrence (P = .003). Univariate analysis revealed that high nuclear protein kinase Cθ expression (P = .046; hazard ratio, 2.2), tumor size less than 2 cm (P = .049; hazard ratio, 4.7), lymph node metastasis (P = .003; hazard ratio, 3.0), and higher stage (P = .002; hazard ratio, 8.7) were each associated with shorter overall survival. We identified the aberrant nuclear expression of protein kinase Cθ in oral squamous cell carcinoma. High nuclear protein kinase Cθ expression may correlate with disease recurrence and poor survival in patients with oral squamous cell carcinoma. © 2012 Elsevier Inc. All rights reserved. ☆ This study was supported by Changhua Christian Hospital (96-CCH-IRP-39) and a grant from the Department of Health, Taiwan (DOH100-TD-C-111-002). ⁎ Corresponding author. Department of Pathology, Changhua Christian Hospital, Changhua, Taiwan. E-mail address: 10159@cch.org.tw (K. -T. Yeh). www.elsevier.com/locate/humpath 0046-8177/$ – see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.humpath.2011.05.001 Human Pathology (2012) 43, 276–281