Patient Characteristics and Patterns of Surgical Interventions in Patients of Differentiated Thyroid Cancer with Distant Metastasis

Abstract

Unlike most head and neck cancers, the presence of distant metastasis (DM) does not preclude curative intent treatment and surgical interventions are common in metastatic disease. DM has an adverse impact on survival and lends considerable morbidity to the patient. This research attempts to study the demographics, patterns of metastasis, and surgical interventions in this rare subgroup of patients with differentiated thyroid cancer (DTC). Materials and methods: Thirty two patients of DTC with radiologically or histopathologically or cytopathologically confirmed DM who underwent surgery at a tertiary care centre from August 2011 to December 2018 formed the study cohort of this retrospective study. Results:The study population comprised 59% females and had a median age of 55 (19-79) years. Thorax was the most common site of metastasis, documented in 56% of patients, while 53% patients had bone metastases. Multiple DM were noted in 8 patients. All patients underwent total thyroidectomy or completion thyroidectomy with or without neck dissection. Surgery for metastatic sites was possible in 14 patients (44%) with debulking and spine fixation being the commonest surgical intervention for metastasis. Thyroidectomy, with or without neck dissection followed by radioactive iodine (RAI) ablation was used as the primary modality to treat DM in patients who did not undergo specific surgical treatment for distant metastases. The median dose of RAI received by patients was 400 (25 -749) mCi, in one to four sessions (median-2 sessions). Three patients received conventional chemotherapy, while four received Sorafenib. Conclusion: Metastasectomy in differentiated thyroid cancer with distant metastases is feasible in selected patients and surgical interventions are most commonly performed on the spine to prevent neurological complications. RAI ablation is universally administered in this subset of patients and in very high doses, often distributed in multiple sessions. The role of chemotherapy and tyrosine kinase inhibitor is still restricted to palliative settings and cost constraints remain a detriment to more widespread use.