Extent of Thyroidectomy Is Not a Major Determinant of Survival in Low- or High-Risk Papillary Thyroid Cancer

Abstract

The optimal extent of thyroidectomy for papillary thyroid cancer (PTC) is controversial. Our objective was to evaluate the effect of total thyroidectomy or partial thyroidectomy on survival in low- and high-risk patients. The Surveillance, Epidemiology, and End Results database was used to identify PTC patients who underwent thyroidectomy. The independent effects of age, distant metastases, extrathyroidal extension, tumor size, sex, lymph node metastases, radioactive iodine use, and extent of thyroidectomy on survival were analyzed for low- and high-risk PTC. There were 4402 (81%) low-risk and 1030 (19%) high-risk patients; 84.9% underwent total thyroidectomy. The 5- and 10-year survival were 95% and 89% in the low-risk patients and 84% and 73% in the high-risk patients, respectively (P = .001). In the low-risk patients, 10-year survival after total thyroidectomy was 89%, compared with 91% after partial thyroidectomy (adjusted hazard ratio for death, 1.73; 95% confidence interval, 1.28-2.33; P < .001); older age, male sex, larger tumor, lymph node metastases, and lack of radioactive iodine were associated with higher mortality. In the high-risk patients, 10-year survival after total thyroidectomy was 72%, compared with 78% after partial thyroidectomy (adjusted hazard ratio for death, 1.46; 95% confidence interval, .89-2.40; P = .14); older age, distant metastases, larger tumors, and lack of radioactive iodine were associated with higher mortality. Survival of patients with PTC was not significantly influenced by the extent of thyroidectomy. The survival after partial thyroidectomy was similar to total thyroidectomy within both the low- and high-risk prognostic groups.