A UK based two-centre review of multifocality and its role in the treatment of papillary thyroid cancer

Multifocality is increasingly observed in papillary thyroid carcinoma (PTC) due to improvements in imaging and histopathological analysis. However, its significance in management, particularly as a sole risk-factor, remains controversial. This study aimed to investigate the prognostic value of multifocality in predicting recurrence following thyroid lobectomy in a contemporary group of PTC patients managed in the UK. Patients with PTC in NHS Lothian (2009-19) and Guys and St Thomas NHS Foundation Trust (2012-19) were identified. Categorical variables were compared using Chi-squared or Fisher's exact test. Five-year recurrence free survival (RFS) were analysed using Kaplan-Meier method and compared using log-rank. Of 828 patients; 492 (59%) had unifocal and 336 (41%) multifocal disease on final pathology. A higher rate of pathological nodal disease (22%v36%,p