Capecitabine Induced Necrotizing Enterocolitis.

Abstract

Capecitabine is an antineoplastic agent belonging to pyrimidine antagonist which is used in the treatment of metastatic colorectal cancer. It is an orally active prodrug of 5-Fluorouracil (5-FU). After absorption it is converted into deoxy-5-fluoridine in the liver and is released into blood. Taken up by cells, it is hydrolyzed to 5-FU by thymidine phosphorylase. 5-FU is metabolized by dihydropyrimidine dehydrogenase(DPD).Since many breast and colorectal cancer cells express large quantity of this enzyme, they generate more 5-FU and suffer higher toxicity than normal cells. A combined regimen of capecitabine and oxaliplatin is frequently used in metastatic colorectal cancer [1] . Capecitabine is registered for treatment of patients following surgery of stage III colon cancer in the adjuvant setting, for treatment of metastatic colorectal cancer, first-line treatment of advanced gastric cancer and for treatment of locally advanced or metastatic breast cancer (European Medicines Agency (EMEA), 2015) [2] . Here we report a case of necrotizing enterocolitis secondary to the use of capecitabine in the treatment of carcinoma stomach stage III and discuss its relevant pathophysiology, clinical presentation and management.Our aim is to create an awareness regarding capecitabine induced necrotizing enterocolitis which is a rare and life threatening adverse event. Case report:A 65years old male was evaluated for abdominal pain, vomiting and loss of appetite. The patient's past medical history shows that he is a known case of COPD and is on inhalers. He is also positive for HbsAG test. Ultrasonography(USG) abdomen done showed suspicious pyloric wall thickening. Oesophago-gastro-duodenoscopy (OGD scopy) done showed growth incisura. Biopsy reports showed poorly differentiated adenocarcinoma stomach. He underwent distal gastrectomy, D2 dissection and esophago jejunostomy. Histopathology reported as tumor size of 8 x 5 x 2 cm, grade III, poorly cohesive carcinoma, margins free and 14/22 lymph nodes positive. He came to hospital for further evaluation and management and was planned for adjuvant chemotherapy with oxaliplatin and capecitabine (capeOX) regimen. The patient successfully tolerated first three cycles of chemotherapy. But post fourth cycle of capecitabine, patient presented with complaints of loose stools and abdominal pain. Diagnosis:Clinical examination showed that the patient's ECOG performance status as 1. The patient was afebrile and vital signs were normal. Post 4 th cycle the patient presented with complaints of giddiness, loose stools and abdominal pain. On clinical examination abdomen was distended and tenderness was positive. USG was done and it showed that the patient got diagnosed with Necrotising enterocolitis. This diagnosis was further confirmed by a CT scan. Blood investigations revealed that the patient have hypokalemia.Corresponding Author:-Athira P V.