Ipsilateral lobectomy versus bilateral lobar resection in papillary thyroid carcinoma: a retrospective analysis of surgical outcome using a novel prognostic scoring system.

From a multivariate analysis of more than 14,200 patient-years' experience with papillary thyroid carcinoma (PTC), we devised a prognostic scoring system based on patient age, tumor grade, extent, and size (AGES). This scoring system can identify patients at increased risk of PTC mortality and was employed as an adjustment variable for analyzing the role of different types of surgical treatment in 860 PTC patients. Cancer mortality at 25 years in patients with an AGES score of 3.99 or less was 1% after ipsilateral lobectomy (n = 131) and 2% after bilateral resection (n = 603), whether subtotal or total (p = 0.15). Of patients with an AGES score of 4 or more, those who underwent lobectomy alone (n = 30) had a mortality rate from PTC at 25 years of 65%, while those undergoing bilateral resection (n = 86) had a lower rate of 35% (p = 0.06). For patients at minimal risk (score of 3.99 or less) of PTC death, no improvement in survival was demonstrable when patients underwent more than ipsilateral lobectomy. However, in a subgroup (score of 4 or more) identified to be at significant risk of PTC death, the survival after bilateral resection was much higher than after ipsilateral lobectomy alone. In neither the "minimal" nor the "higher" risk subgroup was PTC survival significantly improved by the performance of total thyroidectomy.