Purpose: To determine the efficacy and safety of sunitinib in Chinese patients with unresectable or metastatic pancreatic neuroendocrine tumors (pNETs) and the clinical significance of steady-state sunitinib serum concentrations.
Methods: We conducted a multicenter retrospective study including six centers from across China. A total of 60 patients with unresectable or metastatic pNETs who were treated with sunitinib were evaluated retrospectively.
Results: The median overall survival (OS) was 47.5 months and the median time to progression (TTP) was 15.3 months. The objective response rate was 5.0%, and the stable disease (SD) rate was 81.7%. About 35.2% of patients required a dosage decrease from 37.5 to 25 mg/day due to adverse events, which in most cases were alleviated or disappeared with the dosage reduction. In 14 patients who experienced sunitinib-related hypertension, 2 achieved a partial response (PR) and 11 had SD. The median OS and TTP of these 14 patients experienced hypertension were both not reached. The median Css of sunitinib was similar between patients treated with sunitinib 37.5 and 25 mg/day (P = 0.955), but higher in patients who had PR than in those who achieved SD or progressive disease, although no statistically significant difference was found (P = 0.173).
Conclusions: Sunitinib had similar treatment efficacy to western patients with pNET in China. A 25 mg/day dosage was better tolerated than 37.5 mg/day in Chinese patients, and there were no significant differences in sunitinib Css between the two dosage groups. Patients with higher sunitinib Css seem to have better efficacy. Sunitinib-related hypertension may be a predictor of a better treatment effect.
Keywords: Neuroendocrine tumor; Pancreatic; Sunitinib; Treatment.