Tumor size, lesion number, baseline thyroglobulin levels and geographic region appear to be prognostic of progression-free survival (PFS) after treatment with sorafenib in patients with radioactive iodine-refractory differentiated thyroid cancer, according to data presented at the 84th Annual Meeting of the American Thyroid Association.
Results from the DECISION trial, published in The Lancet, demonstrated improved PFS with sorafenib, as compared with placebo, in this patient population, researchers wrote in an abstract. The purpose of this study was to pinpoint prognostic and predictive factors of treatment outcomes, they noted.
In the study, 417 patients were randomly assigned to placebo (n=210) or sorafenib (n=207). Data identified lower maximum individual target lesion size, lower number of lesions, baseline thyroglobulin levels lower than 486 ng/mL and living in Asia vs. Europe or North America as prognostic of longer PFS in the placebo group, as well as all patients after adjustment for treatment.
Subgroup analyses, however, showed that a maximum individual target tumor size of less than 1.5 cm was associated with longer PFS and less benefit from sorafenib treatment compared with lesions of 1.5 cm or greater in size.
In addition, the researchers found that lung metastases and lesions of 1.5 cm or greater in size were predictive of better treatment effect with sorafenib.
Both symptomatic and asymptomatic patients at entry experienced improved PFS after sorafenib treatment, according to the data.
“Based on post-hoc exploratory analyses, patients with progressive [radioactive iodine-refractory differentiated thyroid cancer] and maximum tumor size <1.5 cm appear to have a good prognosis and may be candidates for ‘watch and wait’ before initiating sorafenib,” the researchers wrote.
- Schlumberger M et al. Oral Abstract 13. Presented at: American Thyroid Association (ATA) 84th Annual Meeting; Oct. 29-Nov. 2, 2014; Coronado, Calif.