Purpose: To study whether orgotein is effective in preventing late radiation-induced effects.
Methods and materials: Patients >18 years old who were diagnosed with rectal cancer, had an indication for pelvic irradiation (RT) after surgery, and complied with the selection criteria were randomly assigned at the end of RT to receive orgotein for 7 weeks or no treatment (control). The Radiation Therapy Oncology Group toxicity scale was used to evaluate the RT-induced side effects for up to 2 years. Interruptions due to toxicity, concomitant medication, and non-RT adverse events were also recorded.
Results: A total of 100 patients were included, with 50 in each group. The groups were comparable in terms of the demographic and baseline characteristics. The orgotein group had statistically significant less late toxicity than the control group (p = 0.036) and nontreated patients had a 66% greater chance of developing late toxicity at 2 years. Grouping toxicity as nonrelevant (Radiation Therapy Oncology Group Grade 0-1) and relevant (Grade 2 or worse), patients given orgotein had a lower incidence of late relevant toxicity than did controls, with statistical significance reached at all follow-up visits. After 2 years, patients not treated with orgotein had, in general, a 37% greater chance of developing late relevant toxicity; this risk was 26% when referring specifically to GI toxicity. No adverse events attributable to orgotein were recorded at any time during the study.
Conclusion: Orgotein is a safe treatment that significantly prevents the overall occurrence of late toxicity, with toxicity reduction particularly evident in the lower GI tract.