Predictors of malignancy in STN vs MNG thyroid: Metanalysis

Background: The incidence of thyroid cancer is different between solitarynodular (SN) thyroid and multinodular goiter (MNG). Therefore, a meta-analysis is performed to evaluate the existing literature on the comparative incidence of thyroid cancer in SN versus MNG. Methods: Papers were identified using a systematic search of PubMed/MEDLINE, Cochrane Central, ScienceDirect, GoogleScholar, International Clinical Trials Registry and reference lists of included articles. There are no restrictions on time, study design, language or country of publication. Two independent reviewers screened the most relevant articles according to PRISMA guidelines. Results: Twenty-two studies were included in this analysis and included 50, 321 patients, of which 44.2% were in the STN subgroup and 55.37% were in the MNG subgroup. MNG was significantly associated with a lower risk of thyroid cancer compared to STN (OR=0.76; 95% CI 0.61-0.96). Papillary carcinoma was the most common carcinoma in both groups, followed by follicular and medullary carcinoma. Subgroup analysis was performed to evaluate the effectiveness of the two most commonly used diagnostic tools, surgery and fine needle aspiration cytology (FNAC), but yielded non-significant results, indicating comparable utility between the two. Another subgroup analysis based on participants' assumed iodine status also yielded non-significant results. Conclusion: The incidence of thyroid cancer is higher in patients with STN, but since the available evidence on this topic is of low quality, it is important to carry out larger studies that confirm the association with precision.