Article: Should all papillary thyroid microcarcinomas be aggressively treated- an analysis of 18,445 cases
Xiao-Min Yu, Yin Wan, Rebecca Sippel and Herbert Chen
Ann Surg. October 2011
Article Summary: Yu at al. have analyzed 18,445 cases of papillary thyroid microcarcinoma (PTMC) measuring one centimeter or less by using data available through the Surveillance, Epidemiology and End Result (SEER) Cancer database maintained by the National Cancer Institute for the years 1988-2007. The purpose of the study was to define the long term prognosis of PTMC and to identify risk factors which might portend worse prognosis . Mean primary tumor size was 5.3 mm and mean age 42, most had a total/subtotal thyroidectomy and 26% had a partial thyroidectomy. 30% underwent regional nodal dissection. Overall survival was 95% at 10 years and 91% at 15 years, while disease free survival was 99.3% at 15 years. Identified risk factors for worse prognosis included African American Race, age >45, male sex, presence of extrathyroid extension, lymph node or distant metastases.
Question 1: Would exclusion of incidentally detected lesions in this study or inclusion of multifocal disease seen so commonly in those undergoing total thyroidectomy change the outcomes or conclusions of the study? Could the study be redesigned to include these factors into data analysis?
Question 2: Do these patients with such small tumors really get a regional nodal dissection (ie at least 5 central nodes or more lateral nodes removed) 30% of the time and if so what was the driving force behind that?
Question 3: Given the excellent 15 year disease free survival of patients with PTMC, if patients have none of the risk factors identified in this study that suggest more aggressive disease, could a watchful waiting approach be a therapeutic option in the future? What clinical trials have been done in the past to address this issue and what were the results? Should additional clinical trials be designed to look at non surgical intervention strategies in patients with PTMC and what would be an ideal study design? Why have large randomized clinical trials not been performed to answer important questions in the surgical care of patients with thyroid cancer whereas such trials have been so critical in determining the care of patients with melanoma, breast cancer, and colon cancer?
Please feel free to comment on any or all of the questions above. We look forward to hearing from you, the Annals readers.