Department of Radiation Oncology (Pan JJ,Zong JF,Lin SHJ,Guo QJ),Department of Radiology (Chen YB,Xiao YP),Fujian Provincial Cancer Hospital,Provincial Clinical College of Fujian Medical University and Fujian Provincial Key Laboratory of Translational Cancer Medicine,Fuzhou 350014,China;Department of Clinical Oncology,Pamela Youde Nethersole Eastern Hospital,Hong Kong,China (Ng WT,Chan LLK);Department of Radiation Oncology,Princess Margaret Cancer Centre,University of Toronto,Canada (Sullivan BO);Department of Clinical Oncology,Queen Mary Hospital,Hong Kong,China (Sze HCK);Department of Systems Engineering and Engineering Management,City University of Hong Kong (Choi HCW);Department of Diagnostic Radiology,Pamela Youde Nethersole Eastern Hospital,Hong Kong,China (Kan WK);Department of Biostatistics,Princess Margaret Cancer Centre,Canada (Wei X);Department of Radiation Oncology,Stanford University,USA (Le QT);Department of Clinical Radiology,University of California,San Francisco,USA (Glastonbury CM);Department of Medicine (Oncology),Stanford Cancer Institute,Stanford University,USA (Colevas D);Department of Head and Neck Surgery,University of Texas MD Anderson Cancer Center,USA (Weber RS);Department of Head and Neck Surgery,Memorial Sloan Kettering Cancer Center,USA (Shah JP);Department of Clinical Oncology,University of Hong Kong and Clinical Oncology Center,China (Lee AWM)
Abstract： Objective An accurate staging system is crucial for cancer management. With the development of cancer staging systems and therapeutic methods, the applicability and improvement of staging systems should be evaluated constantly. Methods The clinical data of 1609 nasopharyngeal carcinoma patients without metastasis at initial diagnosis, who were admitted to two tumor centers in Hong Kong and Mainland China and received intensity-modulated radiotherapy (IMRT), were analyzed retrospectively based on the 7th edition of the American Joint Committee on Cancer (AJCC) or International Union Against Cancer (UICC) staging system, and all the patients underwent magnetic resonance imaging (MRI) before treatment. Results Among the T3/T4 patients without involvement of other anatomic structures, overall survival (OS) showed no significant differences between the patients with masticator space (medial pterygoid muscle and/or lateral pterygoid muscle) involvement, prevertebral muscle involvement, and parapharyngeal space involvement. The OS was similar between the patients with extensive soft tissue (soft tissues other than the structures mentioned above) involvement and those with intracranial involvement or cranial nerve involvement. Only 2% of the patients had lymph node metastasis>6 cm above the supraclavicular fossa (SCF), with an OS similar to that of the patients with lower cervical lymph node metastasis. Replacing SCF with the lower neck (below the caudal border of the cricoid cartilage) did not affect the risk difference between different N stages. With the proposed T and N staging systems, the OS showed no significant differences between T4N0-2 and T1-4N3 patients. Conclusions After a review by AJCC/UICC staging system preparatory committees, the changes recommended for the 8th edition include changing medial pterygoid muscle or lateral pterygoid muscle involvement from T4 to T2, adding prevertebral muscle involvement to T2 stage, replacing SCF with the lower neck and combining this with a maximum lymph node diameter of>6 cm as N3 stage, and integrating T4 and N3 as stage ⅠVA. These changes result in a better risk difference between adjacent stages and achieve the optimal balance between clinical practicability and global applicability.
Pan Jianji,Wai Tong Ng,Zong Jingfeng et al. Proposal for the 8th edition of AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity-modulated radiotherapy[J]. Chinese Journal of Radiation Oncology, 2016, 25(3): 197-206.
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