Cancer Epidemiology Biomarkers & Prevention, Vol 7, Issue 11 989-992, Copyright © 1998 by American Association for Cancer Research

ARTICLES

A randomized, placebo-controlled trial of low-dose alpha-difluoromethylornithine in individuals at risk for colorectal cancer

RR Love, R Jacoby, MA Newton, KD Tutsch, K Simon, M Pomplun and AK Verma
Department of Medicine, University of Wisconsin School of Medicine, Madison, USA.

DFMO is an irreversible inhibitor of ornithine decarboxylase (ODC), the key enzyme in mammalian polyamine biosynthesis. The goal of this study was to determine the effects of DFMO 0.5 g/m2/day as a single oral dose on polyamine and ODC levels in rectal, rectosigmoidal, and cecal colonic mucosae of individuals at risk for colon cancer because of a personal history of adenomatous polyps of the colon or a family history of colon cancer in at least one first-degree relative. A second goal was to determine toxicity of this treatment given over 1 year. Forty-five randomized subjects had a flexible sigmoidoscopy with no preparation and a colonoscopy after lavage preparation at baseline, a sigmoidoscopy with no preparation after 3 months, and both procedures (as at baseline) after 12 months, with mucosal biopsies taken from the rectosigmoid area (sigmoidoscopy) or rectal and cecal areas (colonoscopy) for evaluations of ODC and polyamine levels. Significantly decreased levels of putrescine and spermidine were found in rectosigmoid colonic mucosae of DFMO-treated (n = 24) compared with placebo (n = 21) subjects at 3 months (P = 0.03 and 0.04) and 12 months (P = 0.005, P = 0.004). Similar trends, none reaching statistical significance, were found for individual polyamine levels in rectal and cecal mucosae. No significant differences in ODC levels were detected marginally. There was evidence of global suppression of ODC and polyamine levels in the treatment group (P = 0.035). Three DFMO recipients (12.5%) developed clinically noticeable and audiologically demonstrated hearing loss, which was reversible and attributed to DFMO after 3 months (two subjects) and 12 months (one subject). The tissue polyamine changes demonstrated in this study are consistent with findings in other studies in colon and other tissues. The ototoxicity findings here suggest that investigation of other DFMO schedules, such as ones with a drug "holiday," will be a necessary step before Phase III chemoprevention studies can be pursued.

This article has been cited by other articles:

				A. R. Simoneau, E. W. Gerner, R. Nagle, A. Ziogas, S. Fujikawa-Brooks, H. Yerushalmi, T. E. Ahlering, R. Lieberman, C. E. McLaren, H. Anton-Culver, et al. The Effect of Difluoromethylornithine on Decreasing Prostate Size and Polyamines in Men: Results of a Year-Long Phase IIb Randomized Placebo-Controlled Chemoprevention Trial Cancer Epidemiol. Biomarkers Prev., February 1, 2008; 17(2): 292 - 299. [Abstract] [Full Text] [PDF]

				A.-T. Vlastos, L. A. West, E. N. Atkinson, I. Boiko, A. Malpica, W. K. Hong, and M. Follen Results of a Phase II Double-Blinded Randomized Clinical Trial of Difluoromethylornithine for Cervical Intraepithelial Neoplasia Grades 2 to 3 Clin. Cancer Res., January 1, 2005; 11(1): 390 - 396. [Abstract] [Full Text] [PDF]

				C. D. Lao, P. Backoff, L. I. Shotland, D. McCarty, T. Eaton, F. G. Ondrey, J. L. Viner, S. J. Spechler, E. T. Hawk, and D. E. Brenner Irreversible Ototoxicity Associated with Difluoromethylornithine Cancer Epidemiol. Biomarkers Prev., July 1, 2004; 13(7): 1250 - 1252. [Abstract] [Full Text] [PDF]

				H. Guo, R. M. Ray, and L. R. Johnson RhoA stimulates IEC-6 cell proliferation by increasing polyamine-dependent Cdk2 activity Am J Physiol Gastrointest Liver Physiol, October 1, 2003; 285(4): G704 - G713. [Abstract] [Full Text] [PDF]

				V. A. Levin, K. R. Hess, A. Choucair, P. J. Flynn, K. A. Jaeckle, A. P. Kyritsis, W. K. A. Yung, M. D. Prados, J. M. Bruner, S. Ictech, et al. Phase III Randomized Study of Postradiotherapy Chemotherapy with Combination {alpha}-Difluoromethylornithine-PCV versus PCV for Anaplastic Gliomas Clin. Cancer Res., March 1, 2003; 9(3): 981 - 990. [Abstract] [Full Text] [PDF]

				C. J. Fabian, B. F. Kimler, D. A. Brady, M. S. Mayo, C. H. J. Chang, J. A. Ferraro, C. M. Zalles, A. L. Stanton, S. Masood, W. E. Grizzle, et al. A Phase II Breast Cancer Chemoprevention Trial of Oral {alpha}-Difluoromethylornithine: Breast Tissue, Imaging, and Serum and Urine Biomarkers Clin. Cancer Res., October 1, 2002; 8(10): 3105 - 3117. [Abstract] [Full Text] [PDF]

				L. I. Shotland, F. G. Ondrey, K. A. Mayo, and J. L. Viner Recommendations for Cancer Prevention Trials Using Potentially Ototoxic Test Agents J. Clin. Oncol., March 15, 2001; 19(6): 1658 - 1663. [Abstract] [Full Text] [PDF]

				R. F. Jacoby, C. E. Cole, K. Tutsch, M. A. Newton, G. Kelloff, E. T. Hawk, and R. A. Lubet Chemopreventive Efficacy of Combined Piroxicam and Difluoromethylornithine Treatment of Apc Mutant Min Mouse Adenomas, and Selective Toxicity against Apc Mutant Embryos Cancer Res., April 1, 2000; 60(7): 1864 - 1870. [Abstract] [Full Text]

				E. M. Messing, R. R. Love, K. D. Tutsch, A. K. Verma, J. Douglas, M. Pomplun, R. Simsiman, and G. Wilding Low-Dose Difluoromethylornithine and Polyamine Levels in Human Prostate Tissue J Natl Cancer Inst, August 18, 1999; 91(16): 1416 - 1417. [Full Text] [PDF]

				F. L. Meyskens Jr. and E. W. Gerner Development of Difluoromethylornithine (DFMO) as a Chemoprevention Agent Clin. Cancer Res., May 1, 1999; 5(5): 945 - 951. [Abstract] [Full Text] [PDF]