Endocrine Abstracts

Background: Systemic treatment options for metastatic neuroendocrine tumours (NETs) remain limited. The combination of Capecitabine and Temozolomide (CAPTEM) has shown efficacy in pancreatic NETs (PanNETs), but data in small bowel NETs and pulmonary carcinoids are limited. We reviewed our institutional experience with CAPTEM across NET subtypes.

Methods: We retrospectively reviewed records of NET patients treated with CAPTEM from January 2022 to August 2025. Descriptive statistics were used to summarise demographics, disease, and treatment-related information. The treatment regime consisted of capecitabine 1000 mg/m² orally twice daily on days 1–14, combined with temozolomide 200 mg/m² once daily on days 10–14 of a 28-day cycle. Progression-free survival (PFS) was defined as the interval from treatment initiation to disease progression or last follow-up without progression. The data cut-off date was August 30, 2025.

Results: Fifteen patients were identified; 53% female and the median age was 69 years (range 53–78). Tumour grades were 53% grade 2, 26.7% grade 1, and 20% well-differentiated grade 3. Primary tumour sites included pancreas (40%), small bowel (33.3%), lung/thymus (20%), and rectum (6.7%); 40% were functional tumours. CAPTEM was given as first-line therapy in 20% of cases, second-line in 13.3%, third-line in 60%, and fourth-line in 13.3%; 53.3% had prior peptide receptor radionuclide therapy (PRRT). Median treatment duration was 9 months. At 6 months, 80% of patients had stable disease. Median progression-free survival was 9 months overall and 17 months in PanNETs. Reported toxicities included fatigue (grade 1 in 85%, grade 3 in 15%) and gastrointestinal events (grade 1 diarrhoea and nausea in 40%). Diarrhoea was more common in patients with functional NET. Dose reductions were required in 80% of patients. All patients tested negative for DPD deficiency. No significant hematologic toxicity was observed, including in those with prior PRRT.

Conclusion: In this real-world cohort, CAPTEM was well tolerated and demonstrated durable activity in NETs, with particularly favourable outcomes in PanNETs. Importantly, both efficacy and safety were maintained in heavily pretreated patients, including patients who had prior PRRT.