GEMOX regimen in the treatment of metastatic differentiated refractory thyroid carcinoma

Treatment options for radioiodine resistant metastatic thyroid cancer patients are limited, and chemotherapy is considered an outdated therapeutic method for differentiated thyroid carcinoma. In this study, we evaluated the activity and safety of gemcitabine and oxaliplatin combination which is considered an out of label therapeutic method in patients with differentiated metastatic thyroid cancer refractory to 131-I treatment. Fourteen refractory patients (8 papillary, 6 follicular), six men/eight women with median age of 63 years and performance status (0–3) were included. Patients received gemcitabine (1,000 mg/m²) plus oxaliplatin (100 mg/m²) every 2 weeks until 12-cycles and each cycle correspond to 2 weeks treatment. This protocol was approved by the local Institutional Review Boards. Response rate was assessed every four cycles. Progression-free and overall survivals were calculated. Median treatment was 9.5 cycles (range 2–17) with 22 weeks duration. Overall response rate was 57%, with 7% achieving a complete response (1/14), 50% a partial response (7/14), and 28% with a stable disease. All patients with follicular subtype showed objective responses. Eleven patients progressed at a median time of 10.1 months; 10 of 14 patients still alive and the median survival was not reached (median follow-up of 19.8 months). The combination was generally well tolerated. No deaths occurred due to therapy and no grade IV toxicity was recorded. The most common treatment-related adverse events grade 1/3 includes asthenia, peripheral neuropathy, diarrhea, anemia, thrombocytopenia, and neutropenia. In conclusion, the GEMOX regimen is well tolerated and effective in advanced differentiated thyroid cancer. However, this retrospective data on a small sample size are considered preliminary and needs to be evaluated prospectively in a higher number of patients in a clinical trial.