Symptom‐to‐Diagnosis Interval, Treating‐Center Context, and Survival in Nasopharyngeal Carcinoma in Nonendemic Northern China: A Multicenter Real‐World Cohort Study

BACKGROUND: In nonendemic northern China, symptom recognition prompts diagnostic evaluation for nasopharyngeal carcinoma. METHODS: We analyzed 1022 patients with nonmetastatic nasopharyngeal carcinoma treated with definitive-intent intensity-modulated radiotherapy. The symptom-to-diagnosis interval extended from first symptom onset to pathological diagnosis. Logistic and Cox models assessed stage and survival; treating-center analyses used a 2016-2022 common-window cohort. RESULTS: Stages III-IVA disease occurred in 807 patients (79.0%), and 576 (56.4%) had intervals > 3 months. Intervals > 3 months were associated with Stages III-IVA disease (OR 2.52, 95% CI 1.85-3.45) and mortality (HR 1.62, 95% CI 1.28-2.06); after AJCC-stage adjustment, HR 1.29 (95% CI 1.00-1.67). Treatment at participating tertiary general hospitals was associated with higher mortality (HR 1.46, 95% CI 1.07-1.98). Exploratory model-standardized analyses yielded predicted 5-year death differences of 25.99 (4.22-47.68) and 51.47 (26.27-75.50) for treating-center and interval scenarios. CONCLUSIONS: Longer intervals were associated with advanced stage and poorer survival; survival differed by treating-center context.