Open AccessSevere irinotecan-induced toxicity in a patient withUGT1A1*28andUGT1A1*6polymorphisms
Author(s) -
Jianming Xu,
Yan Wang,
FeiJiao Ge,
Lin Li,
Zeyuan Liu,
Manish Sharma
Publication year - 2013
Publication title -
world journal of gastroenterology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.427
H-Index - 155
eISSN - 2219-2840
pISSN - 1007-9327
DOI - 10.3748/wjg.v19.i24.3899
Subject(s) - irinotecan , neutropenia , medicine , sn 38 , colorectal cancer , gastroenterology , pharmacokinetics , toxicity , adverse effect , folfiri , pharmacology , cancer
Many studies have demonstrated the impact of UGT1A1 on toxicity of irinotecan. In particular, patients bearing UGT1A1 28 (TA 7/7) have a higher risk of severe neutropenia and diarrhea. Based on this, prescribers of irinotecan are advised that patients with UGT1A1 28 (TA 7/7) should start with a reduced dose of irinotecan, although a particular dose is not specified. Research in Asian countries has shown a lower incidence of UGT1A1 28 (TA 7/7), while UGT1A1 6 (A/A) is more often found and is associated with severe irinotecan-related neutropenia. We report here a case of a metastatic colorectal cancer patient who is heterozygous for the UGT1A1 28 polymorphism (TA 6/7) as well as the UGT1A1 6 polymorphism (G/A). The patient was treated with FOLFIRI for 9 cycles and underwent two irinotecan dose reductions according to pharmacokinetic data regarding exposure to the active metabolite, SN-38. Simultaneous heterozygous UGT1A1 28 and UGT1A1 6 polymorphisms may produce higher exposure to SN-38 and a higher risk of adverse effects related to irinotecan. Additional studies will be necessary to determine the optimal starting dose of irinotecan for patients with both UGT1A1 28 and UGT1A1 6 polymorphisms.