Kuo EJ, et al. - Researchers performed a population-based study to elucidate risk factors associated with reoperation in medullary thyroid carcinoma (MTC) and disease-specific mortality. As per findings, initial neck dissection could decrease local recurrences in MTC. In appropriately selected patients, reoperation seemed a viable strategy to achieve long-term disease-free survival. Central neck dissection continued to be underused.

Methods

• From January 1, 1999, through December 31, 2012, researchers performed a retrospective analysis of hospital data obtained from the California Cancer Registry and the Office of Statewide Health Planning and Development.
• The analysis was performed from January 1, 1999, to December 31, 2012.
• They identified a population-based sample of 953 patients with MTC.
• In the analysis, inclusion was performed of patients who underwent thyroid surgery and had a minimum postoperative follow-up of 2 years (n = 609).

Results

• Thyroid surgery was performed on 609 patients with MTC; the mean (SD) patient age at diagnosis was 52.6 (17.5) years, and 60.8% (n = 370) of the patients were female.
• The mean (SD) tumor size of 2.8 (2.0) cm was observed.
• Despite published MTC guidelines recommending initial central neck dissection, only 35.5% (216 of 609) of patients underwent central neck dissection at the time of the initial thyroidectomy.
• As per findings, the rate of reoperation was 16.3% (99 of 609), and the median time to reoperation was 6.4 months.
• Increased risk of reoperation was observed with the presence of lymph node metastasis (hazard ratio [HR], 3.43; 95% CI, 2.00-5.90), while central and lateral neck dissection performed at the initial operation was protective (HR, 0.53; 95% CI, 0.30-0.93).
• At a median follow-up of 7.7 years, 45.5% (45 of 99) were disease free among patients who underwent reoperation.
• For the entire cohort , five-year disease-specific mortality was 13.5% (82 of 609).
• For disease-specific mortality, independent risk factors were 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.
• No increased mortality was observed with reoperation.