Postoperative Radiotherapy for Medullary Thyroid Cancer: A Meta-Analysis of Survival and Recurrence Outcomes

Medullary thyroid cancer (MTC) is a rare thyroid carcinoma that often presents at an advanced stage. The efficacy of adjuvant postoperative radiotherapy (PORT) in treating MTC remains a topic of debate. We aimed to assess whether PORT enhances survival outcomes in patients with MTC.

We conducted a systematic review of databases, including EMBASE, PubMed, Cochrane Library, and CINAHL to identify relevant studies. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and local recurrence-free survival (LRFS) were extracted, and pooled analyses were performed using random-effects models.

Ten studies were finally included. Two separate pooled analyses of OS revealed no statistically significant differences between the PORT and observation groups (HR 1.59, 95% CI 0.87-2.92 and HR 1.67, 95% CI 0.92-3.02, including two different National Cancer Database studies with overlapping periods, respectively). Similarly, no significant differences were noted for LRFS (HR 0.90, 95% CI 0.44-1.82; I² = 0%, p = 0.442).

Although PORT did not demonstrate significant differences in survival outcomes compared to observation, personalized treatment considerations are essential due to heterogeneity among high-risk patients. Further prospective studies are required to define optimal adjuvant treatment strategies for MTC.