Kuo EJ, et al. - This study aimed at delineating risk factors associated with reoperation in medullary thyroid carcinoma (MTC) and disease-specific mortality. Findings revealed that for patients with MTC, lymph node dissection might reduce recurrence leading to reoperation. In appropriately selected patients, researchers identified reoperation as a viable strategy for achieving long-term disease-free survival. Central neck dissection remained underused.

Methods

• Researchers performed a retrospective analysis of hospital data obtained from the California Cancer Registry and the Office of Statewide Health Planning and Development from January 1, 1999, through December 31, 2012.
• They identified a population-based sample of 953 patients with MTC.
• The analysis included patients who underwent thyroid surgery and had a minimum postoperative follow-up of 2 years (n = 609).
• Recurrent MTC leading to reoperation and disease-specific mortality were determined.

Results

• 609 patients with MTC who underwent thyroid surgery were identified; the mean (SD) patient age was 52.6 (17.5) years at diagnosis, and the patients comprised of 60.8% (n = 370) female.
• The mean (SD) tumor size of 2.8 (2.0) cm was observed.
• Despite recommendation of initial central neck dissection by published MTC guidelines, only 35.5% (216 of 609) of patients underwent central neck dissection at the time of the initial thyroidectomy.
• In this study, the reoperation rate was 16.3% (99 of 609), and the median time to reoperation was 6.4 months.
• An increase in the risk of reoperation was evident with the presence of lymph node metastasis (hazard ratio [HR], 3.43; 95% CI, 2.00-5.90); on the other hand, central and lateral neck dissection performed at the initial operation proved protective (HR, 0.53; 95% CI, 0.30-0.93).
• At a median follow-up of 7.7 years, 45.5% (45 of 99) of the patients who underwent reoperation were disease free.
• For the entire cohort, five-year disease-specific mortality was 13.5% (82 of 609).
• As per observations, independent risk factors for disease-specific mortality included older age (HR, 1.36 per decade; 95% CI, 1.17-1.59), tumor size greater than 2 cm (HR, 2.83; 95% CI, 1.08-7.44 for >2 to 4 cm and HR, 2.89; 95% CI, 1.09-7.71 for >4 cm), and regional (HR, 4.77; 95% CI, 2.29-9.94) and metastatic (HR, 21.08; 95% CI, 9.90-44.89) disease.
• There appeared no association between reoperation and increased mortality.