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.
Corresponding Authors:
Anne W.M.Lee,Email:awmlee@hku.hk
Cite this article:
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.
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.
[1] Fleming ID,Cooper JS,Henson DE,et al. AJCC cancer staging manual[M].5th ed. Philadelphia,PA:Lippincott-Raven,1997. [2] Sobin LH,Wittekind CH.TNM classification of malignant tumours[M].5th ed. New York,NY:Wiley-Liss,1997. [3] Ho JHC.Stage classification of nasopharyngeal carcinoma:a review[A]//de Teh G,Ito Y.Nasopharyngeal Carcinoma:Etiology and Control[M].Lyon,France:International Agency for Research on Cancer,1978:99-113. [4] Lee AWM,Foo W,Law SCK,et al. Staging of nasopharyngeal carcinoma:from Ho’s to the new UICC system[J].Int J Cancer,1999,84(2):179-187.DOI:10.1002/(SICI)1097-0215(19990420)84:2<179::AID-IJC15>3.0.CO;2-6. [5] Greene F,Page D,Fleming I.AJCC cancer staging manual[M].6th ed. New York,NY:Springer-Verlag,2002. [6] Sobin LH,Wittekind C.TNM classification of malignant tumours[M].6th ed. New York,NY:Wiley-Liss,2002. [7] Sobin LH,Gospodarowicz MK,Wittekind C.TNM classification of malignant tumours[M].7th ed. Oxford,United Kingdom:Wiley-Blackwell,2009. [8] Edge S,Byrd DR,Compton CC,et al. AJCC cancer staging handbook:from the AJCC cancer staging manual[M].7th ed. New York,NY:Springer,2010. [9] Lee AWM,Au JSK,Teo PML,et al. Staging of nasopharyngeal carcinoma:suggestions for improving the current UICC/AJCC staging system[J].Clin Oncol (R Coll Radiol),2004,16(4):269-276.DOI:10.1016/j.clon.2004.01.008. [10] Low JSH,Heng DMK,Wee JTS.The question of T2a and N3a in the UICC/AJCC (1997) staging system for nasopharyngeal carcinoma[J].Clin Oncol (R Coll Radiol),2004,16(8):581-583.DOI:10.1016/j.clon.2004.08.003. [11] Tang LL,Li L,Mao YP,et al. Retropharyngeal lymph node metastasis in nasopharyngeal carcinoma detected by magnetic resonance imaging:prognostic value and staging categories[J].Cancer,2008,113(2):347-354.DOI:10.1002/cncr.23555. [12] Zong JF,Lin SJ,Lin J,et al. Impact of intensity-modulated radiotherapy on nasopharyngeal carcinoma:validation of the 7th edition AJCC staging system[J].Oral Oncol,2015,51(3):254-259.DOI:10.1016/j.oraloncology.2014.10.012. [13] Tang LL,Li WF,Chen L,et al. Prognostic value and staging categories of anatomic masticator space involvement in nasopharyngeal carcinoma:a study of 924 cases with MR imaging[J].Radiology,2010,257(1):151-157.DOI:10.1148/radiol.10100033. [14] Chen L,Liu LZ,Chen M,et al. Prognostic value of subclassification using MRI in the T4 classification nasopharyngeal carcinoma intensity-modulated radiotherapy treatment[J].Int J Radiat Oncol Biol Phys,2012,84(1):196-202.DOI:10.1016/j.ijrobp.2011.11.021. [15] Luo DH,Yang J,Qiu HZ,et al. A new T classification based on masticator space involvement in nasopharyngeal carcinoma:a study of 742 cases with magnetic resonance imaging[J].BMC Cancer,2014,14(1):653.DOI:10.1186/1471-2407-14-653. [16] Zhang GY,Huang Y,Cai XY,et al. Prognostic value of grading masticator space involvement in nasopharyngeal carcinoma according to MR imaging findings[J].Radiology,2014,273(1):136-143.DOI:10.1148/radiol.14132745. [17] Sze H,Chan LLK,Ng WT,et al. Should all nasopharyngeal carcinoma with masticator space involvement be staged as T4?[J].Oral Oncol,2014,50(12):1188-1195.DOI:10.1016/j.oraloncology.2014.09.001. [18] Xiao YP,Pan JJ,Chen YB,et al. The prognosis of nasopharyngeal carcinoma involving masticatory muscles:a retrospective analysis for revising T subclassifications[J].Medicine (Baltimore),2015,94(4):e420.DOI:10.1097/MD.0000000000000420. [19] Feng AC,Wu MC,Tsai SYC,et al. Prevertebral muscle involvement in nasopharyngeal carcinoma[J].Int J Radiat Oncol Biol Phys,2006,65(4):1026-1035.DOI:10.1016/j.ijrobp.2006.02.012. [20] Lee CC,Chu ST,Chou P,et al. The prognostic influence of prevertebral space involvement in nasopharyngeal carcinoma[J].Clin Otolaryngol,2008,33(5):442-449.DOI:10.1111/j.1749-4486.2008.01770.x. [21] Zhou GQ,Mao YP,Chen L,et al. Prognostic value of prevertebral space involvement in nasopharyngeal carcinoma based on intensitymodulated radiotherapy[J].Int J Radiat Oncol Biol Phys,2012,82(3):1090-1097.DOI:10.1016/j.ijrobp.2010.11.063. [22] Som PM,Curtin HD,Mancuso AA.Imaging-based nodal classification for evaluation of neck metastatic adenopathy[J].AJR Am J Roentgenol,2000,174(3):837-844.DOI:10.2214/ajr.174.3.1740837. [23] Ng WT,Lee AWM,Kan WK,et al. N-staging by magnetic resonance imaging for patients with nasopharyngeal carcinoma:pattern of nodal involvement by radiological levels[J].Radiother Oncol,2007,82(1):70-75.DOI:10.1016/j.radonc.2006.11.010. [24] Li WF,Sun Y,Mao YP,et al. Proposed lymph node staging system using the international consensus guidelines for lymph node levels is predictive for nasopharyngeal carcinoma patients from endemic areas treated with intensity modulated radiation therapy[J].Int J Radiat Oncol Biol Phys,2013,86(2):249-256.DOI:10.1016/j.ijrobp.2012.09.003. [25] Pan JJ,Xu YJ,Qiu SF,et al. A comparison between the Chinese 2008 and the 7th edition AJCC staging systems for nasopharyngeal carcinoma[J].Am J Clin Oncol,2015,38(2):189-196.DOI:10.1097/COC.0b013e31828f5c96. [26] Ouyang PY,Su Z,Ma XH,et al. Comparison of TNM staging systems for nasopharyngeal carcinoma,and proposal of a new staging system[J].Br J Cancer,2013,109(12):2987-2997.DOI:10.1038/bjc.2013.659. [27] Yue D,Xu YF,Zhang F,et al. Is replacement of the supraclavicular fossa with the lower level classification based on magnetic resonance imaging beneficial in nasopharyngeal carcinoma?[J].Radiother Oncol,2014,113(1):108-114.DOI:10.1016/j.radonc.2014.08.036. [28] Ng WT,Lee MCH,Hung WM,et al. Clinical outcomes and patterns of failure after intensity-modulated radiotherapy for nasopharyngeal carcinoma[J].Int J Radiat Oncol Biol Phys,2011,79(2):420-428.DOI:10.1016/j.ijrobp.2009.11.024. [29] Lin SJ,Pan JJ,Han L,et al. Nasopharyngeal carcinoma treated with reduced-volume intensity-modulated radiation therapy:report on the 3-year outcome of a prospective series[J].Int J Radiat Oncol Biol Phys,2009,75(4):1071-1078.DOI:10.1016/j.ijrobp.2008.12.015. [30] Schoenfeld DA.Sample-size formula for the proportional-hazards regression model[J].Biometrics,1983,39(2):499-503.DOI:10.2307/2531021. [31] Akaike H.A new look at the statistical model identification[J].IEEE Trans Automat Contr,1974,19(6):716-723.DOI:10.1109/TAC.1974.1100705. [32] Harrell FE Jr,Califf RM,Pryor DB,et al. Evaluating the yield of medical tests[J].JAMA,1982,247(18):2543-2546.DOI:10.1001/jama.1982.03320430047030. [33] Lee AWM,Ng WT,Chan LK,et al. The strength/weakness of the AJCC/UICC staging system (7th edition) for nasopharyngeal cancer and suggestions for future improvement[J].Oral Oncol,2012,48(10):1007-1013.DOI:10.1016/j.oraloncology.2012.03.022. [34] Ferlay J,Soerjomataram I,Ervik M,et al. GLOBOCAN 2012 v1.0,cancer incidence and mortality worldwide:IARC CancerBase No.11[M].Lyon,France:International Agency for Research on Cancer,2013.
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