Subdivision of M category for nasopharyngeal carcinoma with synchronous metastasis: time to expand the M categorization system.

Lu-jun Shen; Si-yang Wang; Guo-feng Xie; Qi Zeng; Chen Chen; An-nan Dong; Zhi-mei Huang; Chang-chuan Pan; Yun-fei Xia; Pei-hong WU

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Subdivision of M category for nasopharyngeal carcinoma with synchronous metastasis: time to expand the M categorization system.

Author: Lu-Jun SHEN ¹ ; Si-Yang WANG ² ; Guo-Feng XIE ³ ; Qi ZENG ⁴ ; Chen CHEN ⁵ ; An-Nan DONG ⁶ ; Zhi-Mei HUANG ⁷ ; Chang-Chuan PAN ⁸ ; Yun-Fei XIA ⁹ ; Pei-Hong WU ¹⁰
Author Information

1. Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. shenlj@sysucc.org.cn.
2. Department of Radiation Oncology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, Guangdong, 519000, P. R. China. 13570608929@163.com.
3. Department of Radiation Oncology, Cancer Center of Guangzhou Medical University, Guangzhou, Guangdong, 510080, P. R. China. 1035124435@qq.com.
4. Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. zengqi@sysucc.org.cn.
5. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. chenchen@sysucc.org.cn.
6. Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. dongan@sysucc.org.cn.
7. Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. huangzhm@sysucc.org.cn.
8. Department of Medical Oncology, Sichuan Cancer Hospital and Institute, Chengdu, Sichuan, 610041, P. R. China. changchuanpan@126.com.
9. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. xiayf@sysucc.org.cn.
10. Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. wuph@sysucc.org.cn.
Publication Type:Journal Article
MeSH: Carcinoma; Humans; Multivariate Analysis; Nasopharyngeal Neoplasms; Neoplasm Staging; Prognosis
From:Chinese Journal of Cancer 2015;34(10):450-458
CountryChina
Language:English
Abstract:
INTRODUCTIONThe current metastatic category (M) of nasopharyngeal carcinoma (NPC) is a "catch-all" classification, covering a heterogeneous group of tumors ranging from potentially curable to incurable. The aim of this study was to design an M categorization system that could be applied in planning the treatment of NPC with synchronous metastasis.
METHODSA total of 505 NPC patients diagnosed with synchronous metastasis at Sun Yat-sen University Cancer Center between 2000 and 2009 were involved. The associations of clinical variables, metastatic features, and a proposed M categorization system with overall survival (OS) were determined by using Cox regression model.
RESULTSMultivariate analysis showed that Union for International Cancer Control (UICC) N category (N1-3/N0), number of metastatic lesions (multiple/single), liver involvement (yes/no), radiotherapy to primary tumor (yes/no), and cycles of chemotherapy (>4/≤4) were independent prognostic factors for OS. We defined the following subcategories based on liver involvement and the number of metastatic lesions: M1a, single lesion confined to an isolated organ or location except the liver; M1b, single lesion in the liver and/or multiple lesions in any organs or locations except the liver; and M1c, multiple lesions in the liver. Of the 505 cases, 74 (14.7%) were classified as M1a, 296 (58.6%) as M1b, 134 (26.5%) as M1c, and 1 was not specified. The three M1 subcategories showed significant difference in OS [M1b vs. M1a, hazard ratio (HR) = 1.69, 95% confidence interval (CI) = 1.16-2.48, P = 0.007; M1c vs. M1a, HR = 2.64, 95% CI = 1.75-3.98, P < 0.001].
CONCLUSIONSWe developed an M categorization system based on the independent factors related to the prognosis of patients with metastatic NPC. This system may be helpful to further optimize individualized care for NPC patients.