Grant: Project Grant

Neuroendocrine tumors (NETs) are cancers that originate from hormone-producing cells in the body. Although uncommon, the number of new cases is increasing. NETs most commonly develop in the lungs or digestive system and surgery is curative if the cancer has not spread (metastasized). Once it has, the goal of treatment is to slow cancer growth and control symptoms to improve patients' quality of life (QOL) and extend the time they live. Drugs called somatostatin analogs (SSA) are often used as a first treatment as they prevent NETs from making hormones and slow down their growth. Inevitably, however, NETs start to grow again, and patients need other treatments. Peptide receptor radioligand therapy (PRRT) using a radioactive form of SSA called lutetium-177 DOTATE is effective after standard SSAs stop working. SSAs are usually continued during and after PRRT treatment, but their value is unknown, they can cause side effects, and have high costs. STOPNET is a phase II randomized trial that aims to determine the feasibility and preliminary results of testing if using SSAs with PRRT is necessary for patients with metastatic NETs from the small intestine and right colon who do not require an SSA to control hormones made by the cancer. A total of 52 patients currently being treated with SSAs but whose NETs have started growing, will be randomized 1:2 to either continue or stop taking an SSA while on PRRT. Patients acceptance, compliance and the proportion of cancer control at 20 months while off SSA treatment will be assessed. QOL, cost, mental health and survival will be analyzed. The Australasian Gastro-Intestinal Cancer Trials Group is leading the trial and the Canadian Cancer Trials Group will conduct the trial in Canada. The trial will generate data to inform feasibility and design of a subsequent larger clinical trial to inform public health decisions and treatment guidelines. STOPNET will also foster international collaboration in clinical research for NETs.