Objective: To determine the relationship between age and rate of lymph node metastasis, nodal burden of disease, as well as rate of lateral neck disease in papillary thyroid cancer, especially in patients aged <30 years.
Study design: Population-based cross-sectional study.
Setting: Population-based cancer database.
Methods: Data were extracted from the SEER 18 database (Surveillance, Epidemiology, and End Results) of the National Cancer Institute. The study cohort included 59,330 patients diagnosed with papillary thyroid cancer between 1988 and 2015. Patients aged 0 to 10 years, 11 to 20 years, and 21 to 30 years old were compared with those >30 years. All analyses were adjusted for sex, race, and T classification.
Results: The overall rate of lymph node metastasis was 26.11%, which increased with decreasing age. Adjusted odds ratios of lymph node metastasis were 7.19 (95% CI, 3.76-13.75) for the 0- to 10-year-old group, 3.45 (95% CI, 3.08-3.87) for the 11- to 20-year-old group, and 2.28 (95% CI, 2.15-2.41) for the 21- to 30-year-old group, relative to the group >30 years old. Decreased age was also associated with increased total positive nodes, increased lymph node ratio, and increased risk of lateral neck disease.
Conclusion: Pediatric and early young adult patients with papillary thyroid carcinoma have a greater risk of lymph node metastasis, greater burden of nodal disease, and a greater risk of lateral neck metastases.
Keywords: SEER program; age; lymph node metastasis; lymph node ratio; papillary thyroid carcinoma.