Differentiated thyroid cancer is the most common type of thyroid cancer and, although surgery and radioactive iodine treatment can be very effective, in some cases the tumor will continue to progress.
Kenneth Burman, Chief of Endocrine at MedStar Washington Hospital Center (Washington DC, USA), and colleagues investigated the effect of sunitinib (already approved for treatment of several other cancers, such as advanced renal cell cancer) in 23 patients with advanced-stage differentiated thyroid cancer, all of whom had undergone at least one course of radioactive iodine treatment. They measured progression-free survival (PFS), as well as the response of tumor growth (using Response Evaluation Criteria in Solid Tumors). Median PFS was reported as 214 days (~8 months).
Sunitinib is a targeted therapy, which inhibits multiple proteins in cancer cells and thus limits cancer cell growth and division. The researchers compared their results against the control group results from a recently published study in patients with the same type of cancer, who were given a placebo, and found that PFS was significantly longer with sunitinib treatment than placebo. Moreover, PFS with sunitinib was comparable with PFS previously reported for sorafenib.
“Sunitinib can potentially be used as an effective adjunctive treatment in patients with advanced differentiated thyroid cancer,” commented Burman.
A total of 83% of sunitinib-treated patients benefited from the treatment, demonstrating either significant tumor shrinkage (n = 6; 26%) or slowed disease progression (n = 13; 57%). “Sunitinib is not a cure but it appears from this study that it may slow the progression of disease,” Burman reported.
Burman commented that sunitinib was generally tolerated well, with most adverse events being only mild or moderate. He advised that a larger, controlled Phase III trial for treatment of advanced differentiated thyroid cancer is warranted.