BACKGROUND: For papillary thyroid cancer (PTC) patients, no consensus has been reached for the impact of diagnosis-to-treatment interval (DTI) on patient survival outcomes. We evaluated the impact of DTI on prognosis among patients with PTC. METHODS: Patients diagnosed as PTC were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2019. The initial treatment strategies include surgery, radiation therapy, chemotherapy, hormone, immunotherapy, and/or active surveillance according to the SEER. Patients were grouped as follows: (I) DTI 0 (interval <
1 month or immediate treatment), (II) DTI 1-3 months, (III) DTI 4-5 months, and (IV) DTI ≥6 months. RESULTS: A total of 168,969 patients with PTC were included in this cohort study. Median follow-up time was 84.0 months. No significant overall survival (OS) difference was observed between patients with immediate treatment and DTI 1-3 months. However, DTI 4-5 months and ≥6 months were associated with poorer OS compared to patients with immediate treatment. Although Kaplan-Meier analysis suggested slight TCSS differences between the delayed and immediate treatment groups, these disappeared after adjusting for tumor characteristics and treatment factors. CONCLUSIONS: A short-term delay (1-3 months) had no significant impact on OS, whereas more than 3 months of DTI resulted in poorer OS. Notably, delayed treatment had no impact on TCSS. These findings suggest that short-term delays are unlikely to affect survival, supporting decision-making flexibility for patients with low-risk PTC within three months of diagnosis.