Total thyroidectomy's association with survival in papillary thyroid cancers and the high proportion of total thyroidectomy in low-risk patients: Analysis of Korean nationwide data

Abstract

Background Papillary thyroid cancer has an excellent prognosis, but the appropriate level of treatment is controversial. We compared survival between total thyroidectomy and less-than-total thyroidectomy, and examined the proportion of patients with papillary thyroid cancer in Korea undergoing total thyroidectomy.

Methods A nationwide sample of 5,230 papillary thyroid cancer patients was included (total thyroidectomy: 4,262, less-than-total thyroidectomy: 968). Using multivariate Cox regression, we compared overall survival and cause-specific survival by the extent of thyroidectomy (total thyroidectomy versus less-than-total thyroidectomy) for a 1:1 optimal match via the propensity score and for the total study population. We also compared overall survival by extent of thyroidectomy and the proportion of total thyroidectomy in different risk groups using papillary thyroid cancer staging systems.

Results We saw no difference in overall survival by extent of thyroidectomy in the propensity score matched population and the total study population (hazard ratio for less-than-total thyroidectomy 0.82, 95% confidence interval 0.52–1.29; hazard ratio for less-than-total thyroidectomy 1.03, 95% confidence interval 0.71–1.48, respectively). Similarly, there were no differences in thyroid cancer–specific survival by extent of thyroidectomy. None of the different risk groups showed differences in overall survival by surgical extent, although total thyroidectomy improved overall survival in older females with larger tumors. The proportion of papillary thyroid cancer patients who received a total thyroidectomy was 80% or greater regardless of risk group classification.

Conclusion Total thyroidectomy had no survival advantage over less-than-total thyroidectomy in Korean papillary thyroid cancer patients except in a specific high-risk group. 80% or more of low-risk papillary thyroid cancer patients received a total thyroidectomy. These results suggest that further patient-centered treatment which considers both quality of life and clinical outcome is needed.