Abstract: Comparison of 2008 Staging System and the Seventh Edition of UICC Staging System forNasopharyngeal CarcinomaGangyi DAI, RenshengWANG, Yutao QIN, Shanshan MA, Shuai XIAO, Guojun HUANG, Piyun SUNCorresponding author:WANG Rensheng, E-mail: wrsgx@yahoo.com.cnDepartment of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, ChinaThis work was supported by Guangxi-funded Research Projects ( No.key 2010011 )Abstract Objective: To compare the staging system of 2008 Staging System and the seventh edition of UICC staging systemfor nasopharyngeal carcinoma and to investigate the reasonableness of them, in an effort of providing references for improvement of2008 staging system. Methods: A total of 100 patients pathologically confirmed with nasopharyngeal carcinoma without distantmetastasis were collected. Based on MRI and clinical features, these patients were staged with the two staging systems. Results:Sixteen patients had involvement in the nasal cavity ( 27 cases according to the seventh edition of UICC staging system ). Three caseshad involvement in the oropharynx ( 11 cases according to the seventh edition of UICC staging system). No difference was found in thenumber of T1 cases and T2 cases between the two staging systems. The number of T3 cases and T4 cases was different, due to theclassification of sinus involvement as T3 in the seventh edition of UICC. The number of N0 cases was exactly the same according toboth of the staging systems. The difference in the number of N1 cases between the two systems was the biggest. There were no caseswith lymph nodes of more than 6cm in the maximum diameter. The staging results with the two staging systems was almost consistentwith the total clinical stage. There were 97 Ⅲ cases and 95 Ⅳ cases, with advanced cases as the vast majority. Conclusion: Theboundaries of the nasopharynx, oropharynx and nasal cavity are different in the two staging systems. And between the two stagingsystems, the T staging is different when the nasal and oropharyngeal are involved. But in the seventh edition of UICC staging system,the nasal and oropharyngeal involvement are accompanied with other factors associated with higher T stage, resulting in no differencein the number of T1 cases and T2 cases. In 2008 staging system, the incidence of pterygoid muscle involvement was 37% ( 37/100 ),100% combined with other T factors of the same stage or higher stage. The value of assessing pterygoid muscle involvement needsfurther investigation. In 2008 staging system, the classification of paranasal sinus involvement as T4, retropharyngeal lymph nodemetastasis as N1a, and N staging with 3cm standard are reasonable. Adjustment can be made in the imaging area of cervical lymph nodesin RTOG (2006) and the imaging boundaries of the supraclavicular area should be identified in order to integrate with the UICCstaging. The standards for MRI diagnosis in both of the two systems need further improvement.Keywords Nasopharygeal carcinoma; Staging; Comparison