Lori Wirth, MD: Let’s go over the case of a 64-year-old man who presented with a solitary neck mass. He had some intermittent shortness of breath and occasional fatigue, but he was otherwise in good health. His past medical history was otherwise unremarkable.
He presented to his primary care physician [PCP] who noticed on exam a hard, low, central neck mass. The PCP’s work-up included labs, and TSH [thyroid-stimulating hormone] was 10.3 µIU/mL. All the other labs were normal. An ultrasound of the neck was also ordered, and this showed a 2.2-cm mass that seemed to be arising from the isthmus of the thyroid gland.
There were several suspicious lymph nodes that ranged in size from 3 mm to 2.2 cm as well. An ultrasound-guided fine-needle aspiration was done of the thyroid mass, which showed that it was consistent with capillary thyroid carcinoma. There were abnormal-looking cells with nuclear enlargement and nuclear grooves, and no colloid was seen.
The patient was referred to surgery, and the patient underwent a total thyroidectomy and a bilateral central neck bisection. Pathology showed a 2.1-cm capillary thyroid cancer that was arising from the isthmus of the thyroid gland and that there was extra thyroidal extension. Three of 7 central compartment nodes were involved. The largest was 1.8 cm, and there was extra nodal extension seen. Thus, the patient was staged as T2N1MX, and the patient was considered to have an ECOG performance status of 0.
The patient was then referred for further treatment and was given radioactive iodine, 150 millicuries. The postiodine scan showed uptake in the neck only, which was considered consistent with some remnant thyroid tissue. Follow-up at 3 months showed that, on levothyroxine, the TSH was 0.2 µIU/mL. Thyroglobulin measured 68 µg/L. A neck ultrasound was done, which showed no evidence of residual disease in the thyroid bed, and there were no suspicious neck nodes.
A chest CT scan was then performed, which showed more than 15 lung nodules. The largest was 1.4 cm. A fine-needle aspiration was done under CT guidance, confirming metastatic capillary thyroid cancer. The patient was considered to have radioiodine-refractory differentiated thyroid cancer, metastatic to the lung. Lenvatinib at a dosage of 24 mg daily was initiated.
This 64-year-old man is otherwise in good health and presented with a thyroid cancer rising in the isthmus: a papillary thyroid cancer with multiple involved neck nodes and high-risk features. Upon further investigation, he was found to have lung nodules. We know that he has radioiodine-refractory disease based on the fact that the lung nodules were biopsy proven and did not pick up radioactive iodine. Therefore, the patient presented with metastatic radioiodine-refractory capillary thyroid cancer.
Overall, for these patients with metastatic iodine-refractory disease, the prognosis is not great even though it’s thyroid cancer. The 10-year survival for this patient population is less than 10%. The median overall survival is less than 5 years.
In the current era of treatment for thyroid cancers, we don’t have great long-term follow-up data from clinical trials to know what the median overall survival is for patients on treatment, such as with MKIs [multikinase inhibitors] like sorafenib and lenvatinib. We know from longer-term follow-up from the SELECT trial with lenvatinib, for example, that the median overall survival is in a number of years with treatment with a lower bound of 31 months. The median overall survival with long-term follow-up is not yet met.
Transcript edited for clarity.
Case Information: A 64-Year-Old Man With Differentiated Thyroid Cancer
Clinical Workup and Initial Treatment
Subsequent Treatment and Follow-up