What is the chemo drug octreotide? how does it work?

Hormone, not chemo: Hi. Octreotide is a synthetic analog of the hormone, somatostatin (NO relationship to a "statin" drug). "Chemo" usually refers to some toxic anti-metabolite that leads to arrest of cell division and/or cell death. Octreotide does not do that. Octreotide reduces hormone secretion from various cell types: insulin from beta cells, glucagon from alpha cells, serotinin from carcinoid tumors, & others

Somtatostatin analog: This mimics somatostatin. A peptide hormone secreted by the pancreas. its job is to antagonize other pancreatic hormones.So think of it as a synthetic somatostatin. It is given as injections in the skin and used to treat different kinds of endocrine tumors. In oncology it is known for its use against carcinoid ( serotonin secreting tumors) and chemotherapy induced diarrhea.