Yang L, et al. - Study's objective was to establish nomograms to effectively predict skeletal metastasis at initial diagnosis (SMAD) and skeletal metastasis-free survival (SMFS) in nasopharyngeal carcinoma (NPC). The prognostic nomograms were established and enabled accurate stratification of distinct risk groups for skeletal metastasis. It seemed to improve counseling and facilitate individualized management of patients with NPC.

Methods

• In order to develop individual nomograms for SMAD and SMFS, 2685 patients with NPC who received bone scintigraphy (BS) and/or 18F–deoxyglucose positron emission tomography/computed tomography (18F–FDG PET/CT) and 2496 patients without skeletal metastasis were retrospectively assessed.
• By using separate cohorts of 1329 and 1231 patients treated at two other institutions, the models were validated externally.

Results

• Each nomogram incorporated five independent prognostic factors.
• Results revealed a significantly higher c-index in SMAD nomogram than the TNM staging system (training cohort, P = 0.005; validation cohort, P < 0.001).
• In comparison to the TNM staging system, the SMFS nomogram had significantly higher c-index values in the training and validation sets (P < 0.001 and P = 0.005, respectively).
• By using the nomograms, three proposed risk stratification groups were created, and enabled significant discrimination of SMFS for each risk group.