Diarrhea is a common side effect of treatment with chemotherapy and radiation to the pelvis for patients with anal and rectal cancers. Diarrhea is not only an inconvenient side effect but can also be life-threatening if not adequately managed. It may lead to dehydration; electrolyte imbalance; low immune function; malnutrition due to reduced absorption of nutrients; and inflammation, pain and/or bleeding as a result of the increased frequency of bowel movements. If not adequately managed, diarrhea may also result in delays or interruption in treatment.
Sandostatin is a drug approved by the U.S. Food and Drug Administration to treat diarrhea and flushing associated with advanced carcinoid tumors and watery diarrhea associated with VIP (vasoactive intestinal polypeptide)–secreting tumors.
In this study, researchers evaluated 233 patients with anal or rectal cancer who were undergoing treatment with chemotherapy and radiation therapy. Patients were randomly assigned to receive either two doses of long-acting Sandostatin or a placebo. Patients on the Sandostatin arm were administered the drug four to seven days prior to undergoing treatment as well as on day 22 of radiation therapy.
The incidence of acute diarrhea was 49% in the placebo group and 44% in the group that was treated with Sandostatin. In addition, researchers reported that there was no significant difference in patient-reported quality of life and bowel function.
These researchers concluded that Sandostatin was ineffective in the prevention of diarrhea in anal and rectal cancer patients undergoing treatment with chemotherapy and radiation therapy.
 Zachariah B, Gwede CK, James J, et al. Octreotide Acetate in Prevention of Chemoradiation-Induced Diarrhea in Anorectal Cancer: Randomized RTOG Trial 0315. J Natl Cancer Inst [early online publication]. March 25, 2010.