Effect of Graves' disease on the prognosis of differentiated thyroid carcinoma: a meta-analysis

Purpose Several studies have reported different findings on the prognosis of differentiated thyroid carcinoma combined with Graves' disease. To assess the effect of Graves' disease on differentiated thyroid carcinoma, a meta-analysis was undertaken. Methods PubMed, OVID and the Cochrane Library were systematically searched for trials published prior to Oct. 2018. Studies containing data on the outcomes of Graves' disease with differentiated thyroid carcinoma were included. Summary estimates of the prevalence of recurrence/disease progression/persistence and mortality as well as odds ratios and weighted mean differences were calculated with a random-effects model. Results Of the 916 related articles found, 13 fulfilled the inclusion criteria. The recurrence/disease progression/persistent rate was not significantly different between the Graves' disease group and the non-Graves' disease group (P = 0.86). However, the analysis of three studies with K-M curves or HRs showed that there was a significant difference between the two groups (P = 0.04). Subgroup analysis showed that the contradictory results could be due to the location/race assessed in the studies. Graves' disease almost acted as a risk factor (OR = 1.77, 95%C.I. = 0.99-3.16) for differentiated thyroid carcinoma in European studies. When heterogeneous studies were excluded, the analyses show that GD was a risk factor for recurrence/disease progression/persistence (P = 0.03, OR = 1.75, 95%C.I. = 1.04-2.95). The overall mortality rate was significantly higher in the Graves' disease group than in the non-Graves' disease group (P = 0.02, OR = 2.93, 95%C.I. = 1.17-7.37). Conclusions Graves' disease acts as a risk factor for the prognosis of differentiated thyroid carcinoma. The recurrence/disease progression/persistent rate may be affected by TSAbs in a specific location/race and with a genetic immunization background. However, the histotypes and subtypes may play an important role in mortality rate.