P-22 Frequency of dihydropyrimidine dehydrogenase (DPD) deficiency detection and adverse events in patients receiving fluoropyrimidine-based therapy in a pancreatic and biliary tract cancer cohort

Pancreatic and biliary tract cancers (BTCs) are associated with extremely poor prognoses due to patients frequently presenting at an advanced stage, limited treatment options lack of screening programmes. Treatment for these malignancies may involve a 5-fluorouracil (5-FU)-based chemotherapy regimen. requires Dihydropyrimidine dehydrogenase (DPD) catabolism. deficiency occurs gene (DPYD) mutation increases the risk experiencing 5-FU toxicity adverse effects. This retrospective study aimed determine DPD frequency in pancreatic BTCs (all stages) who received 5-FU-based tertiary referral centre assessed events (AEs) as per Common Terminology Criteria Adverse Events (CTCAE) version 5. Patients commencing were identified. The institution database was used access patient records, review evidence DPYD mutation, type cancer, assessment tolerance CTCAE or BTC had been tested eligible study. Details regimens each any subsequent alteration dose also reviewed. Between 06/07/2020 19/04/2021, all (100%) 291 starting regimen deficiency. Of 198 83.8% palliative setting, 8.6% adjuvant 8.1% neoadjuvant. 93 BTC, 60.2% 37.6% 2.2% total cohort tested, 9.3% deficiency; 17 (8.6%) cancer 10 (10.8%) underwent 50% reduction dose). Three mutations identified overall cohort: c.1129-5923C>G (15 (5.2%)), c.2846A>T (9 (3.1%)), c.1905+1G>A (3 (1.0%)). In entire (N = 21, N 11 palliative)), 90% experienced AEs; 73.7% grade 1 AE, 47.7% 2 36.8% 3 AE. most common AEs diarrhoea, neutropenia, thrombocytopenia. No 4 Furthermore, 11.1% 21 given tolerated escalation 75% standard dose, 7.4% required decrease, 19% treatment-related cessation therapy. increase 100%. provides reference frequencies pancreas receiving chemotherapy. cohort, even reduced 5-FU, some requiring either further 5-FU. However, minority 75%.