P-215 06-methylguanine DNA methyltransferase deficiency and outcomes with CAPTEM in patients with pancreatic neuroendocrine tumours

The combination of capecitabine plus temozolomide (CAPTEM) represents a standard-of-care option for the treatment advanced pancreatic neuroendocrine tumours (pNET). 0 6 -methylguanine DNA methyltransferase ( MGMT ) loss expression, assessed by immunohistochemistry (IHQ), has been suggested to be predictive response alkylating agents, such as temozolomide, but remains controversial. We aim analyse outcomes with CAPTEM scheme and examine prognostic relevance status tested IHQ its value in patients metastatic pNET. performed an unicentric retrospective analysis (p) pNET undergoing from Apr/2008 Feb/2023. deficiency was determined IHQ. cut-off 10%, defined negative 2 Fisher test correlate patients’ characteristics Kaplan Meier analyze progression-free survival (PFS) overall (OS) deficient intact. 20p were included. Age (median): 62 [46-77]. Males (45%). Tumour grade (G): G1 (15%), G2 (55%) G3 (20%). Ki-67 proliferative index: detected 12p (60%). 15p (75%) debuted stage IV. Most frequent sites liver (95%) lymph nodes (30%). 70% had elevated baseline chromogranin (>100ng/mL) 2p hormonally functioning tumours. 11p underwent 1L therapy 9p previously received 1 or more lines treatment. Somatostatin analogues used concurrently In population, median PFS 41m (95%CI;0.0-83.8) OS 141.9m (95%CI;0.0-303.1). recorded objective rate (ORR) 60% normalisation levels at reassessment 21.4% patients. A higher tumour associated worse prognosis terms (p=0.05) (p=0.01). At time analysis, 41.6% (≥3% we observed marked trend towards better (88m [95%CI;19.5-156.4] vs 11.1m [95%CI;0.0-32.2]; p=0.02). Median strongly lower intact (35.8m [95%CI;0.1-71.4] [95%CI;0.0-302.7]; p=0.03). ORR reported those (60% 40%; p=0.64). is prolonged high pNET, line pivotal studies. Our findings suggest that could biomarker identify who are likely respond agents. However, standardization this technique needed evaluated prospective