Effect of a prostaglandin--given rectally for prevention of radiation-induced acute proctitis--on late rectal toxicity. Results of a phase III randomized, placebo-controlled, double-blind study.
OBJECTIVE
To assess the late effect of a prostaglandin, given rectally during irradiation, on late rectal toxicity. In the acute treatment setting no significant differences in reducing the incidence of acute proctitis symptoms in patients receiving misoprostol, however, significantly more rectal bleeding had been reported.


METHODS
A total of 100 patients who had undergone radiotherapy for prostate cancer had been entered into this phase III randomized, placebo-controlled, double-blind study with misoprostol or placebo suppositories. The toxicity was evaluated yearly after cessation of irradiation by the RTOG/LENT-SOMA scale.


RESULTS
The median follow-up was 50 months. 20 patients suffered from grade 1, four patients from grade 2 as well, and three patients only from grade 2 toxicity. Frequency, bleeding and urgency were the most commonly reported symptoms. In keeping with other studies and clinical experience, the symptoms peaked within the first 2 years with a median for grade 1 of 13 months and for grade 2 of 15 months. The presence of acute toxicity grade 2 showed a correlation with the development of any late toxicity (p = 0.03). Any acute rectal bleeding was significant correlated with any late rectal bleeding (p = 0.017).


CONCLUSIONS
Misoprostol given as once-daily suppository for prevention of acute radiation-induced proctitis does neither influence the incidence and severity of radiation-induced acute nor late rectal toxicity. Misoprostol has no negative impact on the incidence and severity of late rectal bleeding, in contrast to acute rectal bleeding. The routine clinical use of misoprostol suppositories cannot be recommended.
Kertesz
Tereza
T
Department of Radiotherapy and Radiooncology, University of Göttingen, Robert-Koch-Strasse 40, Göttingen, Germany.
Herrmann
Markus K A
MK
Zapf
Antonia
A
Christiansen
Hans
H
Hermann
Robert M
RM
Pradier
Olivier
O
Schmidberger
Heinz
H
Hess
Clemens F
CF
Hille
Andrea
A
D000285:Administration, Rectal; D000368:Aged; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000627:therapeutic use; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016595:Misoprostol / Q000008:administration & dosage / Q000627:therapeutic use*; D011349:Proctitis / Q000209:etiology / Q000517:prevention & control*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects*; D013997:Time Factors
D000897:Anti-Ulcer Agents; D016595:Misoprostol