Do Lower-Risk Thyroid Cancer Patients Who Live in Regions with More Aggressive Treatments Have Better Outcomes?

Background: The management of differentiated thyroid cancer has traditionally consisted of total thyroidectomy with or without adjuvant radioactive iodine. However, in the last two decades, this approach has been challenged, with the consideration of more conservative approaches such as less radical surgery and deferring adjuvant treatment, especially in lower-risk patients. The objective of this study was to consider the effectiveness of current treatment options by comparing the survival outcomes from different geographic regions with different treatment philosophies. This study design was based on the concept of natural experiments in patient care that occur when physicians in different regions treat the spectrum of typical patients with varying treatments.

Method: This population-based retrospective cohort study investigated 2444 patients with differentiated thyroid cancer ≤4 cm between 1990 and 2001 from Ontario, Canada. Extent of disease and extent of surgery were abstracted from pathology reports and were linked to downstream administrative medical information on treatments and outcomes. Patient demographics, tumor characteristics, treatments, and outcomes were compared between those geographic regions with more aggressive treatments and those regions with less aggressive treatments.

Results: Treatment varied across the province. When comparing outcomes in regions where patients had more extensive treatment to those in regions where patients had less extensive therapy, similar rates were found for 15-year survival, recurrence, and survival after recurrence.

Conclusion: There were significant variations in treatment but no differences in outcomes for regions with more versus less aggressive approaches. These findings support the trend toward more conservative management approaches in the treatment of thyroid cancer.