Pentoxifylline and Vitamin E Treatment for Prevention of Radiation Induced Side Effects in Women with Breast Cancer: A Phase Two, Double Blind, Placebo Controlled Randomised Clinical Trial (Ptx-5).

Abstract

Abstract Background: A previous study has shown that pentoxifylline in combination with vitamin E can reverse radiation induced fibrosis. Our aim in the present study was to investigate if the same drugs could prevent radiation induced side effects in women with breast cancer.Patients and Methods: A randomised, placebo-controlled, double blind, parallel group trial was performed. Women with breast cancer were treated for 12 months with pentoxifylline 400 mg t.i.d. or placebo, in combination with vitamin E 100 mg t.i.d. starting 1-3 months after the completion of radiotherapy. The primary endpoint was passive abduction of the shoulder, and the secondary endpoint was difference in arm volumes. The trial is registered on the ISRCTN.org website, number ISRCTN39143623.Results: 83 patients were included in the study; 42 in the pentoxifylline + vitamine E group and 41 in the placebo + vitamine E group. Both treatments were generally well tolerated. Seven patients were withdrawn from treatment due to disease progression; four in the pentoxifylline group and three in the placebo group. At inclusion patients had impaired passive abduction of the shoulder. During treatment both groups improved significantly. With one year of follow-up median improvement from baseline was 3.7° (p=0.0035) in the pentoxifylline group and 9.4° (p= 0.0041) in the placebo group, but no difference between the groups was detected (p=0.20). Arm volumes increased over time in the placebo group (1.04%), but not in the pentoxifylline group (0.50%). This difference between the groups was statistically significantl(p=0.0172).Conclusions: The combination of pentoxifylline and vitamin E was safe and may be used for prevention of some radiation induced side effects. We found that pentoxifylline in combination with vitamin E diminished development of lymphoedema.(Accepted for publication in European Journal of Cancer)Updated results with longer follow-up will be presented. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4100.