Co-medication with hydrolytic enzymes in radiation therapy of uterine cervix: evidence of the reduction of acute side effects

Abstract

Purpose: The use of additional therapy with an oral enzyme preparation containing trypsin, chymotrypsin and papain has been suggested for the reduction of toxicity due to radiation therapy. This study was conducted to test the efficacy and tolerability of this enzyme combination in preventing or reducing the acute side effects of radiation therapy in patients with locally advanced cervical cancer. Methods: A prospective, randomised, open, clinical trial was carried out on 120 patients (aged 24–85 years) with locally advanced, biopsy-proven carcinomas of the uterine cervix (stages IIa, IIb or IIIb). Patients received 50 Gy of external radiation therapy over a period of 5 weeks, followed by intra-cavitary brachytherapy (20–30 Gy). Patients assigned to the test group (60 patients) received additional treatment with enzymes. Patients were evaluated at weekly intervals for acute radiation therapy-related side effects, according to the RTOG/EORTC grading criteria, and then after the end of radiation therapy for another 8 weeks. Occurrence of adverse events, if any, was also recorded. Results: The study revealed that the maximum extent of acute radiation side effects was reduced in the enzyme group: skin reactions (mean: 0.97 vs 1.68 in the control group, P < 0.001), vaginal mucosal reactions (0.55 vs 0.85, P=0.10), genitourinary symptoms (0.93 vs 1.38, P < 0.001) and gastrointestinal reactions (1.12 vs 1.30, P=0.12). The sum-scores during treatment, expressed as area under the curve, were significantly less in the enzyme treated patients. In the follow-up visits all observed side effects of radiation therapy were of lower intensity in the enzyme group than in the control group. Conclusions: In patients with locally advanced cancer of the uterine cervix, oral enzyme therapy was found to be effective in significantly reducing radiation therapy-related side effects such as genitourinary symptoms, subcutaneous changes and reactions of the vaginal mucosa.