The efficacy of capecitabine and temozolomide for the treatment of metastatic neuroendocrine tumors: Memorial Sloan-Kettering Cancer Center experience.

Abstract

363 Background: Emerging literature has suggested the benefit of capecitabine/temozolomide (C/T) therapy in metastatic pancreatic NETs (pNETs) as first line therapy. We conducted a retrospective analysis of the efficacy of (C/T) therapy in all patients with metastatic NETs treated at MSKCC. Methods: Using the electronic pharmacy database, we included all patients’ ≥ 18 years of age who received C/T combination therapy for pNETs between 1/2003-10/2010. Primary endpoint was the overall response rate (ORR). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Response rates were evaluated by a radiologist using CT scans and per RECIST 1.1. MGMT tumor expression was conducted to correlate with response. Results: Twenty patients (mean age 64, 35% female) were identified. There were 16 (80%) pNETs (1 functional, 15 nonfunctional), 2 (10%) carcinoid, 1 high grade biliary (5%) and 1 (5%) gastric neuroendocrine carcinoma. Eight tumors were low grade (1 carcinoid, 7 pNET), 8 intermediate grade (7 pNET, 1 carcinoid), and 4 high grade (2 pNET, 1 stomach, 1 biliary). Twelve (60%) received C/T in the first-line setting and 8 in the relapsed setting. Six (30%) had a partial response and 7 (35%) had stable disease. There were no complete responses ( Table 1 ). With a median follow-up of approximately 3 years, the PFS was 16.4 months. Four pNET patients had unresectable disease at presentation and 2/4 were resected and rendered free of disease after C/T therapy. There were no high grade responders. Liver tumor burden (0%, <10%, 10-50%, >50%), number of prior treatments, and tumor grade did not predict response. Grade 3-4 events potentially related to C/T included neutropenia (1/20, 5%), nausea (3/20 15%), diarrhea (1/20, 5%), and fatigue (3/20, 15%). Conclusions: Combination C/T for the treatment of pNETs is an effective regimen for well differentiated NETs irrespective of tumor burden and prior treatment. No responses were seen in our carcinoid patients. MGMT expression will be presented at the meeting. [Table: see text]