Background. Multivariate evaluation showed that number of metastatic sites (more than three vs. three or fewer), spine involvement (present vs. absent), and treatment modality (CRT vs. chemotherapy or SB 203580 radiotherapy only) were independent prognostic factors for OS. In stratified analysis, compared with chemotherapy or radiotherapy alone, combined chemoradiotherapy could significantly benefit the patients with single bone metastasis (hazard ratio: 0.21; 95% confidence interval: 0.09C0.50). Conclusion. Metastasis to the spine and having more than three bone metastatic sites are independent unfavorable predictors for OS in NPC patients with bone-only metastasis. Combined chemoradiotherapy should be considered for patients with single bone metastasis. 2015; 20:291C298 Implication for Practice: Establishing rigorous subdivision of the M1 stage of bone-only metastatic nasopharyngeal carcinoma (NPC) patients will facilitate disease assessment and treatment planning for clinicians. In our study, we found that the number of metastatic sites and spine involvement were independent prognostic SB 203580 factors for overall survival of NPC patients with bone-only metastasis; combined chemoradiotherapy (CRT) could potentially benefit the patients with single bone metastasis. By subdividing the M1 stage of the patients according to the two prognostic elements, we are able to better forecast the prognosis of patients and facilitate treatment planning. Moreover, combined CRT is recommended for NPC patients with single bone metastasis. Introduction The tumor-node-metastasis (TNM) classification, which describes the anatomic extent of cancer, is widely used to aid clinicians and investigators in planning treatment, assessing prognosis, and facilitating communication [1, 2]. T refers to the extent of the primary tumor, N refers to the lymphatic involvement, and M describes distant metastasis. A series of modifications of the primary tumor (T) and local node (N) elements were introduced in the TNM staging system of nasopharyngeal carcinoma (NPC) in recent years [3C6], primarily because of the progress in diagnostic imaging, radiation techniques, and chemotherapy regimens. The metastatic (M1) stage is still a catch-all classification, with patients who differ in terms of the specific organs involved and the number and location of lesions in each organ. Subdividing the M1 stage for patients with metastatic NPC may help clinicians stratify patients according to prognosis and make therapeutic decisions [7, 8]. Bone is the most frequent involved organ by metastasis among patients with NPC, with an estimated incidence rate of 54%C80% in that group [9C12]. The frequently involved metastatic sites included spine, pelvis, and ribs, and the prognosis of SB 203580 patients with NPC and bone metastasis varied, with occasional long-term survivors [13C15]. Past research in identifying prognostic factors among different types of cancer, such as breast cancer [16], hepatocellular carcinoma [17], and non-small cell lung cancer [18], suggested that bone metastasis patients with different metastatic sites and numbers of lesions may SB 203580 differ greatly in terms of survival. In NPC, growing evidence shows that long-term survival and complete response can be obtained among a small proportion of patients with bone metastasis, especially for those with SB 203580 only a solitary lesion and received aggressive treatment [19]. To date, no study specifically evaluating the associated prognostic factors from M1 stage among TM4SF2 patients with bone-metastatic NPC has been reported. In addition, there is no standard treatment for NPC patients who developed bone metastasis because of the limited number of studies with small numbers of cases due to their rarity. In this study, we aimed to subdivide the M1 stage of NPC patients with bone-only metastasis at diagnosis and to evaluate the treatment effect of combined chemoradiotherapy (CRT) among different M1 patient groups. Methods and Patients Individuals The medical information of just one 1,027 individuals with NPC who have been diagnosed with faraway metastasis at Sunlight Yat-sen University Cancers Middle (SYSUCC) from January 1998 to Dec 2007 were evaluated. This scholarly research was authorized by the SYSUCC medical center ethics committee, which waived the necessity for written educated consent due to the retrospective nature from the scholarly study. The inclusion requirements included bone-only metastasis during preliminary staging or created bone tissue metastasis as the 1st recurrence site during follow-up and receipt of systemic chemotherapy and/or regional radiotherapy after metastasis. The exclusion requirements included treatment at another medical center after analysis of metastasis before entrance to our organization and advancement of other faraway metastasis within.