Value of tumor growth rate in evaluating the early therapeutic efficacy of neuroendocrine neoplasm

Abstract

Objective: To determinate the value of tumor growth rate (TGR) in evaluating the efficacy of early drug treatment for neuroendocrine neoplasm (NEN). Methods: Patients with NEN who treated at Chinese Academy of Medical Sciences Cancer Hospital from January 2010 to December 2018 were retrospectively enrolled. A total of 30 patients (16 males and 14 females, aged from 26 to 73 (53±11) years) were enrolled. The sum of largest diameter of target lesions and the interval time were measured, TGR of 3 months after the first treatment was calculated using a formula. Intraclass correlation coefficient (ICC) were used to test the repeatability of TGR. Receiver operating characteristic curve (ROC) analysis was used to determine the optimal cut-off values of TGR for predicting progression-free survival (PFS). Overall patients and SD patients assessed by RECIST were grouped by the optimal cut-off values of TGR. Kaplan-Meier method was used to estimate PFS rates and plot patient survival curves of patients at different group of TGR. Cox risk proportional hazard model was used to assess the effect of TGR on the prognosis. Results: The optimal cut-off value of TGR was -5.8(%/m), the area under the curve was 0.921 (95%CI: 0.824-0.999, P<0.001). Interobserver ICC was 0.955 (95%CI: 0.907-0.978,P<0.001). Multivariate Cox analysis showed that compared with the patients with TGR<-5.8, the patients with TGR ≥-5.8 had a higher risk of progression in either overall population (HR: 10.906, 95%CI: 1.953-60.898, P=0.006) or the SD population (HR: 14.354, 95%CI: 1.602-128.627, P=0.017); TGR ≥-5.8 was an independent risk factor affecting the prognosis of NEN. Conclusions: TGR can evaluate the efficacy of NEN's early anti-tumor drug treatment, and associate with prognosis.