Autoimmune thyroid disease (AITD) co-exists in 15-25% of papillary thyroid carcinoma (PTC), with likely favourable outcome (1,2). However, the association between PTC with AITD and PTC with BRAF mutation is unclear. We conducted a systematic review with meta-analysis to evaluate:
We searched PubMed, Embase and Web of Science Core Collection for observational studies published from 2010 to June 2023 on adult PTC patients. Studies with data on PTC subsets for presence and absence of BRAF mutation, AITD and CLND were included. For analysis, groups were categorised as “exposed”:(i) BRAF PTC with AITD; (ii a) CLND with BRAF PTC; (ii b) CLND with AITD; and as “control”:(i) BRAF PTC without AITD; (ii a) CLND without BRAF PTC; (ii b) CLND without AITD.
Out of 699 studies initially identified, screening resulted in 44 studies with total of 30 141 PTC patients, mean age of 44 years, 68.3% with BRAF mutant PTC and 24.7% with AITD. Summary statistics of 38 studies showed PTC with AITD had a lower odds of PTC with BRAF mutation with pooled log odds ratio (LOR) of - 0.55 (95% CI-0.69 to -0.41, p <0.001). However, there was significant heterogeneity with I2 of 74.1 % (df 37.0;p<0.001). 10 studies showed BRAF PTC was associated with increased risk of CLND with pooled LOR of 0.49 (95% CI 0.18 to 0.81;p=0.002). In the same studies, PTC with AITD resulted in lower risk of CLND with LOR of -0.45 (-0.69 to -0.22;p=0.002).
Thus, concurrent AITD in PTC has a negative association with BRAF mutation. Risk of CLND is lower in PTC with AITD compared with PTC with BRAF mutation.