Oral Presentation ESA-SRB 2023 in conjunction with ENSA

Tall Cell Papillary Thyroid Cancer: The Westmead and Royal North Shore experience (#166)

Louis Britten-Jones 1 , Spinder Samra 2 , David Goltsman 2 , Gideon Sandler 2 , Matti Gild 1 3 , Christian Girgis 1 2
  1. University of Sydney, Darlinghurst, NSW, Australia
  2. Westmead Hospital, Sydney, Sydney, NSW, Australia
  3. Royal North Shore Hospital, Sydney, NSW, Australia

Aims

This multicentre retrospective cohort study aimed to further develop understanding of tall cell subtype papillary thyroid cancer (tcPTC) by analysing presentation, treatment, and outcomes, as compared to classical papillary thyroid cancer (cPTC). Longitudinal analysis was undertaken to establish risk factors associated with early recurrence and to determine the significance of tall cell histology as an independent prognostic factor.

Methods

Clinicopathological and treatment data was collected for tcPTC and cPTC patients treated at Westmead Hospital between 2013 and 2023 and tcPTC patients treated at Royal North Shore Hospital between 2018 and 2023. Thyroglobulin and thyroglobulin antibody levels were collected to classify biochemical response. Further neck surgeries were used as a surrogate marker of structural recurrence.

Results

Presentation and treatment were analysed for 416 patients (n=51 for tcPTC, n=365 for cPTC). On univariate analysis, tcPTC was found to present at an older age (53.6 years v 46.4 years, p<0.01), with greater rates of positive surgical margins (31.37% v 16.44%, p<0.05), and greater rates of microscopic (47.06% v 22.74%, p<0.001) and gross extrathyroidal extension (15.69% v 6.30%, p<0.05). Radioactive iodine (RAI) therapy was more frequently given to tcPTC patients (66.67% v 41.09%, p<0.001). Longitudinal analysis was conducted for 236 patients (n=24 for tcPTC, n=212 for cPTC). Multivariate analysis found no difference in the odds of developing early recurrence between the tcPTC cohort and the cPTC cohort (OR=0.65, p>0.1). Positive surgical margins (OR=2.84, p<0.005) and lymphovascular invasion (OR=2.73, p<0.005) were independently associated with early recurrence.

Conclusions

tcPTC displays more aggressive features than cPTC at time of diagnosis and is treated more aggressively. Positive surgical margins and lymphovascular invasion were found to be independent predictors of early recurrence, but tall cell histology itself was not. This indicates that more aggressive treatment may not be warranted for all patients with tcPTC.