Efficacy of peptide receptor radionuclide therapy in combination with capecitabine and temozolomide in neuroendocrine tumors: A systematic review and meta-analysis.

Abstract

e16345 Background: The combination of Peptide Receptor Radionuclide Therapy (PRRT) and Capecitabine with Temozolomide (CAPTEM) is emerging as a promising treatment for patients with neuroendocrine tumors (NETs). PRRT targets tumor cells with radiolabeled peptides for localized radiation, while CAPTEM enhances antitumor activity and radiosensitization, demonstrating improved progression-free survival (PFS) and overall survival (OS) in NETs patients. This study aims to provide a comprehensive evaluation of the efficacy of the PRRT and CAPTEM combination in treating NETs. Methods: A comprehensive literature search on PubMed, ClinicalTrials.gov, Cochrane, Google Scholar, and Embase was conducted per PRISMA guidelines. Of 589 articles, 5 studies reporting outcomes of NETs after treatment with PRRT and CAPTEM were selected for final analysis. Three studies were retrospective, and two were prospective trials. Data for Kaplan-Meier survival curves were extracted using Plot Digitizer and analyzed using the MetaSurvival package in R version 4.2.1. The inter-study variance was calculated using the DerSimonian-Laird estimator proportions, and a 95% Confidence Interval (CI) was extracted to compute a pooled analysis. Results: Our analysis included 127 patients with neuroendocrine tumors (NETs) who received PRRT combined with CAPTEM. The median age was 55 (21-81) years and 60% were male (n = 76). Of 15 reported patients, 53% had an ECOG status of 0, and 47% had an ECOG status of 1. Pancreatic NETs were the most common 63% (n = 80) followed by bowel NETs 15% (n = 19). The liver was the most frequent metastatic site (60%, n = 77), followed by lymph nodes (21.2%, n = 27). Prior treatments included surgery (27%), somatostatin analogs (39%), chemotherapy (26%), and radiation therapy (6%). The median follow-up was 23.6 months (range 4.1–71). A complete response was observed in 9 patients (7%), with a cumulative partial response rate of 45% (95% CI: 0.24-0.66, p = 0.00) and a cumulative stable disease rate of 32% (95% CI: 0.22-0.43). Survival rates at 6, 12, 18, and 24 months were 93.35%, 87.50%, 84.62%, and 76.13%, respectively. The pooled median overall survival (mOS) was 47.36 months, with an estimated mean OS of 41.66 months (95% CI: 29.91–47.52). The pooled median progression-free survival (mPFS) was 28.66 months. Conclusions: The combination therapy of PRRT and CAPTEM has demonstrated promising efficacy in treating neuroendocrine tumors, significantly improving response rates and survival outcomes. However, further studies and larger clinical trials are needed to validate these findings and optimize treatment protocols.