Abelleira, Erika1; Schmidt, Angelica1; Bueno, Fernanda1; Pitoia, Fabián1
1 Division of Endocrinology, Hospital de Clínicas, University of Buenos Aires, Argentina
Background: Distant metastases (mainly lungs) are a rare situation in patients with differentiated thyroid cancer (DTC). Two thirds of these patients will become refractory to radioiodine therapy (RAI) and when progression occurs, they will be amenable for treatment with multikinase inhibitors (MKIs)1.
Objectives: To define the time of progression free survival (PFS) and the overall survival (OS) in RAI refractory pulmonary metastases.
Methods: We analyzed 610 files of patients with DTC, 9.8% (n=60) had pulmonary metastases. Thirty-one patients were included after exclusion of those with diffuse RAI uptake, aggressive histology and those who were rendered disease free after RAI. Progressive disease was defined as an increase of at least 30% in pulmonary lesions bigger than 1 cm or identification of new lesion/s. The time of progression was divided in: fast (<1 year), moderate (1 a 5 years) or slow (>5 years).
Results: The median OS was 15 years since DTC diagnosis and 5 years since the development of distant metastases. The median time of PFS was 3.75 years. Time of progression was moderate in 59%, fast in 23.5% and slow in 17.5%; 71% progressed at the end of follow-up. Shorter PFS was associated with age older than 45 years (P = 0.005), metastases larger than 1 cm (P = 0.03) or in multiple sites (P = 0.01) and follicular histology (P =0.01).
Conclusion: RAI-refractory pulmonary metastases usually progresses in 3 to 5 years after initial therapy. This will probably be the moment to start therapy with a MKI.
- Schlumberger M, Brose M, Elisei R, Leboulleux S, Luster M, Pitoia F, Pacini F. Definition and management of radioactive iodine-refractory differentiated thyroid cancer. Lancet Diabetes Endocrinol 2014; 2(5):356–8.