Understanding Pathways to the Diagnosis of Thyroid Cancer: Are There Ways We Can Reduce Over-Diagnosis?

BACKGROUND: The incidence of thyroid cancer has rapidly increased and ecological evidence suggests this is due in some part, to over-diagnosis. Understanding pathways to diagnosis could help determine whether unnecessary diagnosis can be avoided. METHODS: We recruited a population-based sample (n=1007) of thyroid cancer patients diagnosed between July 2013 and August 2016 from Queensland, Australia (response rate 67%). We used information from structured telephone interviews to describe diagnostic pathways for thyroid cancer, to investigate factors associated with diagnostic pathways, and to assess the most prevalent modes of diagnoses by which the lowest-risk, potentially over-diagnosed thyroid cancers (intra-thyroidal micro-carcinomas) are detected. RESULTS: Only 38% of participants presented with symptoms potentially related to thyroid cancer. Older age at diagnosis was associated with a lower prevalence of symptomatic diagnosis (prevalence ratio [PR]: 0.46; 95% confidence interval [CI] 0.31-0.68, for 70-79 vs