In many cancers, octreotide has been reported to control the diarrhea that can accompany chemotherapy. However, for patients receiving combined chemotherapy and radiation for anal or rectal cancers, the drug proved no better than a placebo in a randomized trial that was published online March 24 in the Journal of the National Cancer Institute.
Chemotherapy and radiation, given concurrently, are standard treatments for anorectal cancers, and the side effects of the combined therapy can include acute diarrhea, often so severe that patients must delay or discontinue treatment or be treated with lower doses, compromising the chances of cure.
As noted in a news release, to see whether octreotide could reduce diarrhea in anorectal cancer patients, Babu Zachariah, MD, Clement Gwede, PhD, and colleagues in the Radiation Therapy Oncology Group conducted a randomized, controlled, double-blinded trial. Patients were assigned to receive either a 30 mg dose of long-acting octreotide or a placebo between four and seven days before the start of radiation therapy and again about three weeks later. A total of 215 patients were included in the final analysis.
The rates of acute diarrhea were similar in the two groups. The researchers found no statistically significant differences in the number of patients who had to modify their treatment doses or schedules. There were likewise no differences between the groups in rates of hospitalization, usage of other medical resources, or quality of life.
“In this study,” the authors concluded, “the prophylactic use of [long-acting octreotide acetate] did not prevent the incidence or reduce the severity of diarrhea and had no notable impact on patient-reported bowel function or quality of life.”
The authors noted that the study did not account for the surgical status of the patients and the bowel-sparing techniques that can reduce the incidence of diarrhea.