J Cancer 2018; 9(5):797-806. doi:10.7150/jca.22663 This issue
1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China
2. State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
3. Department of Oncology, The affiliated hospital of Luzhou medical college, Luzhou, People's Republic of China
4. Department of Radiation Oncology, The first affiliated hospital of Bengbu medical college, Bengbu, People's Republic of China
5. Department of Radiation Oncology, Anhui Provincial Hospital, Hefei, People's Republic of China
6. Department of Radiation Oncology, The people's hospital of Guangxi zhuang autonomous region, Nanning, People's Republic of China
7. Department of Medical Oncology, Sichuan Cancer Hospital and Institute, Chengdu, People's Republic of China
8. Departments of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China
Background: To establish a prognostic score based on clinical routine factors to stratify nasopharyngeal carcinoma patients with bone metastasis into risk groups with different survival rates.
Materials and Methods: Total 276 patients from multicenter were retrospectively analyzed. Kaplan-Meier method and Cox regression were used to confirm independent risk factors, which were checked for internal validity by bootstrapping method. The prognostic score, deriving from the corresponding regression coefficients in Cox model, classified patients into low and high risk groups. Finally, two independent cohorts were used for external validation.
Results: In development cohort, six risk factors were identified: age>46 year-old (point=1), N>0 stage (point=2), anemia (point=2), bone metastasis free interval≤12 months (point=1), without radiotherapy to primary sites (point=1), and without radiotherapy to first metastasis sites (point=1). The derived prognostic score divided patients into low (score, 0-4) and high (score, 5-8) risk groups, with highly significant differences of 5-year overall survival rates (high vs. low risk: 24.6% vs. 58.2%, HR 3.47, P<0.001). Two external validations presented congruent results.
Conclusion: A feasible and applicative prognostic score was successfully established and validated to discriminate bone metastatic nasopharyngeal carcinoma into low/high risk groups, which will be useful for individual treatment.
Keywords: Prognostic score, nasopharyngeal carcinoma, bone metastasis, validation, multicenter.