P-328 Dihydropyrimidine dehydrogenase deficiency frequency and its impact on 5-fluorouracil (5-FU) based chemotherapy toxicity

5-fluorouracil (5-FU) and its prodrug capecitabine are Fluoropyrimidines, widely used in colorectal cancer. The prevention of adverse effects related to severe toxicity Fluoropyrimidines essentially involves pre-therapeutic screening for dihydropyrimidine dehydrogenase (DPD) deficiency, which must be carried out systematically before starting treatment with fluorouracil or since the joint HAS/INCa recommendations December 2018. objective our study is assess frequency DPD deficiency impact on occurrence toxicities deficiency. We a retrospective files patients treated, during year 2022 2023, cancer by chemotherapy and/or targeted therapy an adjuvant palliative situation based capecitabine, at level Medical Oncology department CHU Tlemcen. collected 100 patients. Sex ratio 0.7, average age was 58 years. All were treated chemotherapy, localized disease 68 (68%), locally advanced 04 (4%) metastatic 27 (27%). Liver metastases found 20 phenotypic assay within tests 90 (90%). A partial 11 (12%) motivating reduction 2/3 doses. Despite this reduction, noted 09 (10%) type gastrointestinal 06 patients, no discontinuation recommended. For 79 without (87%), 73 (92%) reported mainly 55 (61%), cutaneous 23 (25%) hematological (12%). Asthenia 31 (34%). modified dose (24%) stopped 5 (6%) following serious toxicities: two episodes grade IV hand-foot syndrome 03 acute coronary 02 There increased risk (grade 3 4) liver despite absence search allows adaptation FU doses avoid major toxicity. However, other parameters may also have role toxicity, namely deterioration function cardiac drugs.