Hepatic activation of irinotecan predicts tumour response in patients with colorectal liver metastases treated with DEBIRI: exploratory findings from a phase II study.

Abstract

PURPOSE:

The response of colorectal liver metastases to the cytotoxic agent irinotecan varies widely. Attempts to correlate tumour metabolism with response have been mixed. This study investigated the hepatic metabolism of irinotecan as a potential predictor of tumour response to irinotecan-eluting beads (DEBIRI).

METHODS:

Ten patients with colorectal liver metastases were treated with 200 mg irinotecan (as DEBIRI) as part of the PARAGON II study. Hepatic expression of key metabolising enzymes was measured using mass spectrometry-based proteomics. Serum drug concentrations and hepatic irinotecan metabolism were characterised and correlated with tumour response.

RESULTS:

Serum concentrations of irinotecan metabolites did not correlate with hepatic metabolism or pathological response. There was a strong correlation between hepatic CES-2 expression and activation of irinotecan (r (2) = 0.96, p < 0.001). Patients with a UGT1A1*28 6/7 SNP showed no difference in drug metabolism or pathological response. Hepatic CES-2 mediated activation of irinotecan clearly correlated with tumour replacement by fibrosis (r (2) = 0.54, p = 0.01).

CONCLUSION:

This study provides the first evidence that hepatic activation of irinotecan predicts tumour response. Delivery of liver-targeted irinotecan to normal liver tissue rather than tumour may be a more rational approach to maximise response.

• Authors: R P Jones, P Sutton, R M D Greensmith, A Santoyo-Castelazo, D F Carr, R Jenkins, C Rowe, J Hamlett, B K Park, M Terlizzo, E O'Grady, P Ghaneh, S W Fenwick, H Z Malik, G J Poston, N R Kitteringham
• Journal: Cancer chemotherapy and pharmacology (Cancer Chemother Pharmacol) Vol. 72 Issue 2 Pg. 359-68 (Aug 2013) ISSN: 1432-0843 [Electronic] Germany
• PMID: 23756919 (Publication Type: Clinical Trial, Phase II, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Phytogenic
• DNA, Neoplasm
• Neoplasm Proteins
• Irinotecan
• UGT1A1 enzyme
• Glucuronosyltransferase
• Camptothecin

Topics

• Antineoplastic Agents, Phytogenic (administration & dosage, metabolism, therapeutic use)
• Biotransformation
• Blotting, Western
• Camptothecin (administration & dosage, analogs & derivatives, metabolism, therapeutic use)
• Colorectal Neoplasms (drug therapy, secondary, surgery)
• DNA, Neoplasm (genetics, isolation & purification)
• Drug Delivery Systems
• Genotype
• Glucuronosyltransferase (genetics)
• Humans
• Irinotecan
• Liver (enzymology, metabolism)
• Liver Neoplasms (pathology)
• Mass Spectrometry
• Microsomes (metabolism)
• Neoplasm Proteins (metabolism)
• Prospective Studies
• Reproducibility of Results