COX-2 inhibitors are a class of drugs that have been shown to have some anti-tumor activity against human prostate cancer, both in the lab and in tests on humans. German researchers wanted to find out if combining COX-2 inhibitors with radiation therapy causes more severe side effects than radiation alone. They conducted a Phase I trial to test this.

Twenty-two patient were recruited for the trial. They received 400 mg twice daily of Celebrex (Celecoxib) from the start of the radiation treatment. Radiation doses ranged between 70 and 74 Gy standard fractionation ( overall, a little on the low side by today’s standards). The patients were asked about gastrointestinal (GI) and genitourinary (GU) acute toxicity once a week during radiation therapy, at six weeks after therapy and three month after completing radiation treatment.

“Generally no major increase in the level and incidence of side effects potentially caused by the combined treatment was observed.” In two cases a generalised skin rash occurred, which immediately resolved upon discontinuation of the drug. No grade 3 and 4 toxicity was seen. Maximal GI toxicity grade 1 and 2 was observed in 85% and 10%, respectively. In terms of GU toxicity 80 % of the patients experienced a grade 1 toxicity and 10 % had grade 2 symptoms.

Conclusion — “The combination of irradiation to the prostate with concurrent high dose celecoxib was not associated with an increased level of side effects.”

Source: Combination of celecoxib with percutaneous radiotherapy in patients with localised prostate cancer – a phase I study.Radiat Oncol. 2006 Apr 10;1(1):9. Ganswindt U, Budach W, Jendrossek V, Becker G, Bamberg M, Belka C. CCC Tubingen, Centre for Genitourinary Oncology, Department of Radiation Oncology, University of Tubingen, Tubingen, Germany.