Does sunitinib have a patient-specific dose without diminishing its antitumor effect on advanced pancreatic neuroendocrine neoplasms?

Purpose Because it is unknown whether adjusting the dose of sunitinib can benefit patients with pancreatic neuroendocrine neoplasms (Pan-NENs), this retrospective study examined maximum tumor shrinkage rates and prognoses in patients with and without low doses of sunitinib administration. Methods Eighty-seven patients with metastatic and unresectable neoplasms, treated with sunitinib for > 1 month, were divided into a low-dose (LD) or high-dose (HD) group. The tumor response rates were investigated over time using computed tomography according to the response evaluation criteria in solid tumors criteria. Results The LD and HD groups included 42 and 45 patients, respectively. There were no differences in baseline characteristics (tumor size, Ki-67 index, mitosis, and differentiation) between the two groups. Progressive disease (PD), stable disease (SD), and partial response (PR) were observed in 16.7, 54.8, and 28.6% of patients in the LD group, respectively, and in 13.3, 60, and 26.7% of patients in the HD group, respectively. There were no differences in tumor shrinkage rates between the two groups ( p = 0.87). The 3-year progression-free survival rates for the LD and HD groups were 2.4% and 2.3%, respectively ( p = 0.67), and the 3-year overall survival rates were 57.9% and 70.5%, respectively ( p = 0.76). The occurrence of adverse events was similar between the two groups (61.9% vs. 60.0%, p > 0.95). Conclusions Dose reduction of sunitinib did not alter tumor shrinkage rates or prognoses for patients with advanced Pan-NENs.