LAKE BUENA VISTA, FLA. – Weekly infusions of paclitaxel delayed progression in some patients with the very aggressive anaplastic thyroid cancer, a small prospective study determined.
The drug was most effective as adjuvant therapy for patients who had already undergone chemotherapy plus resection of the primary tumor, Dr. Naoyoshi Onoda reported in a poster session at the International Thyroid Conference. They survived for a median of 1 year (112-788 days) – an impressive feat considering that most patients with anaplastic thyroid cancer die within 6 months of diagnosis.
This finding suggests a place for paclitaxel as a standardized therapy for such patients, said Dr. Onoda of Osaka (Japan) City University. “We have objective data supporting standardized chemotherapy for the first time in the world.”
Anaplastic thyroid cancer is a very rare – but very aggressive – disease; there is no standardized treatment option. Dr. Onoda and his colleagues conducted a national prospective open-label study of weekly paclitaxel infusions in 56 patients with the malignancy.
The cohort was a median of 71 years old. All had stage IV disease: 10 were grade A, 18 grade B, 24 grade C, and four grade X. They received 80 mg/m2 infusions once a week. The median number of cycles was 2, although it ranged from 0-23 cycles.
Almost everyone (98%) experienced adverse events; the most common was anemia (77%). About a quarter (28%) experienced adverse events of at least grade 3, but there were no serious events and no deaths related to the study drug.
The objective response rate and the clinical benefit rate were 23% and 79%. The agent was not curative; at the last follow-up, no patient had achieved a complete response, and 43 of 56 in the study had died of their disease. “Overall, the median time to progression was only 47 days, and median overall survival just 227 days. That is so very short. But it’s a little bit longer than we had been seeing rates from reported cases,” he said at the meeting held by the American Thyroid Association, Asia-Oceania Thyroid Association, European Thyroid Association, and Latin American Thyroid Society.
The study was sponsored by the Prospective Clinical Study Committee of the Anaplastic Thyroid Carcinoma Research Consortium of Japan (ATCCJ). Dr. Onoda had no financial disclosures.