Multifocality as a prognostic factor in thyroid cancer: A meta-analysis

Background: Thyroid cancer is one of the most common endocrine cancers whose incidence has been steadily increasing. Previous studies have suggested that multifocality in thyroid cancer is associated with poor prognosis. The present study aims to quantify the data on multifocality as a factor indicating poor prognosis by meta analysis. Methods: A systematic search was carried out using the electronic databases PubMed and Medline. We searched for articles containing keywords of multifocality and thyroid cancer, as well as risk factors and prognostic factors for thyroid cancer (Lymph node metastases, extrathyroidal extension, distant metastases, disease recurrence, Age, tumour size. and gender). Data sets containing hazard ratios and odds ratios were then compared. Results: The meta-analysis was performed using a total of 21 articles, showed that multifocality is associated with an increased risk of development of LNM (12 Studies: OR = 1.87; 95% CI = 1.51-2.32; I2 = 49.11; p-value = .03), Extrathyroidal extension (15 Studies: OR = 3.18; 95% CI = 0.69-14.71; I2 = 95.62; p-value < .001), Tumour Size > 1 cm (3 Studies: OR = 2.75; 95% CI = 1.95-3.89; I2 = 0.00 and p-value < .88) and disease recurrence (5 Studies: HR = 2.81; 95% CI = 1.07-7.36; I2 = 95.85; p-value < .001). Risk factors that did not significantly contribute to a higher incidence of multifocality include Age > 45, Male Gender. Conclusions: Multifocality in thyroid cancer is a significant risk factor for disease progression and increases the risk of disease recurrence. The present study suggests that patients who have multifocal disease should therefore be managed more aggressively from an operative and post-operative perspective.